Billing Basics — CLF-C02 practice questions

Practice questions for this topic, with explained answers.

Domain: Billing, Pricing, and Support ·100 questions · 30 easy · 40 intermediate · 30 hard · page 2 of 7

Question 16 clf-billing-basics-016

Hard · Choose one

A company owns regional Reserved Instances that cover the instance family its application uses. During a period of high demand, the application fails to launch instances in the Availability Zone it depends on. What explains this outcome?

  1. a Regional Reserved Instances reserve capacity, but only for instances launched with dedicated tenancy
  2. b Regional Reserved Instances provide a billing discount only and do not reserve capacity, so the company needs zonal Reserved Instances or On-Demand Capacity Reservations for capacity assurance
  3. c Regional Reserved Instances reserve capacity only after the reservation has been active for 30 days
  4. d Regional Reserved Instances reserve capacity only when purchased with the All Upfront payment option
Show answer & explanation

Answer: B

Why B is correct

Scope determines whether a Reserved Instance carries a capacity reservation. Regional scope buys flexibility, meaning the discount applies in any Availability Zone in the Region and, for Linux/Unix with default tenancy, across sizes in the family, but AWS documentation states plainly that a regional Reserved Instance does not reserve capacity. Capacity assurance requires zonal scope or an On-Demand Capacity Reservation. Because zonal and regional Reserved Instances cost the same, the choice between them is purely about flexibility versus capacity assurance.

Why the others are wrong

  • A — Tenancy is an attribute the reservation must match to apply the discount. It does not turn a regional reservation into a capacity reservation.
  • C — There is no waiting period after which a regional Reserved Instance begins reserving capacity. Regional scope never reserves capacity.
  • D — The payment option affects only the discount and the cash-flow profile. It has no effect on capacity reservation behavior.

Last verified: 2026-09-01

Question 17 clf-billing-basics-017

Hard · Select 2 answers

Which TWO statements about Savings Plans and Reserved Instance discounts in AWS Organizations are correct? (Choose TWO.)

  1. a Turning discount sharing off normally reduces the organization's total monthly bill
  2. b The management account controls whether Reserved Instance and Savings Plans discount sharing is turned on for accounts in the organization
  3. c A discount applies first to the account that owns the commitment, and any unused benefit can then be shared with other accounts in the organization
  4. d Commitments purchased by a member account can never be shared with any other account
  5. e Savings Plans reserve Amazon EC2 capacity in the purchasing account's Availability Zone
Show answer & explanation

Answer: B and C

Why B and C are correct

Consolidated billing pools usage across the organization so that commitments are used as efficiently as possible. AWS applies a Reserved Instance or Savings Plans benefit to the owning account first, then makes any remaining benefit available to other accounts whose usage matches. The management account is the one that controls discount sharing preferences for accounts in the organization, which is what lets a central finance team decide whether commitments are pooled or ring-fenced.

Why the others are wrong

  • A — AWS warns that deactivating discount sharing can result in higher monthly bills, because unused commitment in one account can no longer offset matching usage in another.
  • D — Commitments bought by a member account are shared across the organization by default once sharing is enabled; ownership determines priority, not eligibility.
  • E — No Savings Plan reserves capacity anywhere. Savings Plans are purely a billing discount mechanism.

Last verified: 2026-09-01

Question 18 clf-billing-basics-018

Hard · Choose one

A company holds Microsoft SQL Server licenses that qualify for License Mobility through Software Assurance. It must run the workload on hardware that is not shared with other AWS accounts, but it does not need visibility into sockets or cores and does not need control over instance placement. Which option meets the requirement with the least configuration overhead?

  1. a Shared-tenancy On-Demand Instances
  2. b Spot Instances launched into a placement group
  3. c Dedicated Instances
  4. d Dedicated Hosts with host affinity configured
Show answer & explanation

Answer: C

Why C is correct

Dedicated Instances run on hardware dedicated to a single AWS account, which satisfies the isolation requirement, and AWS documents SQL Server with License Mobility through Software Assurance as a supported bring-your-own-license scenario for them. Because the company needs neither hardware visibility nor placement control, Dedicated Instances deliver the requirement without the additional allocation and capacity management that Dedicated Hosts entail.

Why the others are wrong

  • A — Shared tenancy places instances on hardware that may be shared with other AWS accounts, which fails the isolation requirement outright.
  • B — Placement groups control how instances are positioned relative to one another for networking and resilience. They do not provide single-tenant hardware, and Spot capacity can be reclaimed at any time.
  • D — Dedicated Hosts would satisfy the requirement, but they require the customer to allocate and manage host capacity and to track instance placement, which is unnecessary overhead when no per-socket or per-core license needs to be accounted for.

Last verified: 2026-09-01

Question 19 clf-billing-basics-019

Hard · Choose one

A company has a workload it is certain will run unchanged for three years and it can pay the full commitment in advance. Which purchase yields the deepest discount off On-Demand pricing?

  1. a A 1-year Standard Reserved Instance with the All Upfront payment option
  2. b A 3-year Convertible Reserved Instance with the All Upfront payment option
  3. c A 3-year Standard Reserved Instance with the No Upfront payment option
  4. d A 3-year Standard Reserved Instance with the All Upfront payment option
Show answer & explanation

Answer: D

Why D is correct

Three variables drive the size of a Reserved Instance discount: term length, payment option, and offering class. The deepest discount comes from combining the longest term, the largest upfront payment, and the least flexible offering class. A 3-year Standard Reserved Instance paid All Upfront maximizes all three at once. AWS states directly that a longer term produces a bigger discount and that a higher upfront payment saves more money.

Why the others are wrong

  • A — A one-year term produces a noticeably smaller discount than a three-year term, and it leaves two years of the known workload uncovered.
  • B — Convertible reservations sacrifice discount depth in exchange for the right to exchange the reservation later. With requirements known to be stable for three years, that flexibility is paid for and never used.
  • C — No Upfront spreads the cost over discounted hourly charges across the term, which improves cash flow but produces the smallest discount of the three payment options.

Last verified: 2026-09-01

Question 20 clf-billing-basics-020

Easy · Choose one

How does AWS charge for data transferred into AWS from the internet?

  1. a It is charged at the same per-GB rate as data transfer out to the internet
  2. b There is no charge for data transfer in from the internet
  3. c It is charged at half the rate of data transfer out to the internet
  4. d It is charged only after the first 100 GB each month
Show answer & explanation

Answer: B

Why B is correct

AWS does not charge for data transfer from the internet into AWS. This asymmetry is deliberate: it removes any cost penalty for moving data into the cloud, which supports migration and ingest-heavy workloads. Charges apply to data leaving AWS for the internet and to certain traffic between Availability Zones and Regions, so cost-aware architecture concentrates on egress and on where data crosses those boundaries.

Why the others are wrong

  • A — Inbound and outbound transfer are priced very differently. Outbound to the internet is metered and tiered; inbound is free.
  • C — There is no half-rate inbound charge. Inbound data transfer from the internet is free of charge.
  • D — The 100 GB per month free allowance applies to data transfer out to the internet, aggregated across AWS services and Regions, not to inbound transfer.

Last verified: 2026-09-01

Question 21 clf-billing-basics-021

Easy · Choose one

Which Amazon S3 storage class stores data in a single Availability Zone in exchange for a lower storage price?

  1. a S3 Standard
  2. b S3 One Zone-Infrequent Access
  3. c S3 Glacier Flexible Retrieval
  4. d S3 Standard-Infrequent Access
Show answer & explanation

Answer: B

Why B is correct

S3 One Zone-IA stores objects in a single Availability Zone, which is why it costs less per GB than S3 Standard-IA. The saving comes with a real risk transfer: if that Availability Zone is lost, the data is lost. AWS positions it for re-creatable data such as secondary backup copies or data replicated from another Region, where the customer can tolerate that exposure.

Why the others are wrong

  • A — S3 Standard is the default class and stores data redundantly across a minimum of three Availability Zones. It costs more per GB than the infrequent-access and archive classes, but it stores data in several Availability Zones rather than one.
  • C — S3 Glacier Flexible Retrieval is an archive class that stores data across a minimum of three Availability Zones, with retrieval measured in minutes to hours.
  • D — S3 Standard-IA stores objects redundantly across a minimum of three Availability Zones. It shares One Zone-IA's infrequent-access pricing shape but not its single-Availability-Zone design.

Last verified: 2026-09-01

Question 22 clf-billing-basics-022

Easy · Choose one

A company must retain compliance archives for seven years. The data is almost never accessed, and when it is, a retrieval time measured in hours is acceptable. Which Amazon S3 storage class gives the lowest storage cost?

  1. a S3 Glacier Deep Archive
  2. b S3 Standard-Infrequent Access
  3. c S3 Intelligent-Tiering
  4. d S3 Glacier Instant Retrieval
Show answer & explanation

Answer: A

Why A is correct

S3 Glacier Deep Archive is the lowest-cost storage class AWS offers and is designed for data retained for years and accessed once or twice a year at most. Its retrieval options are Standard, which completes within 12 hours, and Bulk, which completes within 48 hours, and it carries a 180-day minimum storage duration charge. When the access pattern genuinely tolerates hours of latency, no other class is cheaper per GB.

Why the others are wrong

  • B — S3 Standard-IA is priced for data accessed occasionally but needed immediately. For seven-year archives that are effectively never read, it is far more expensive per GB than an archive class.
  • C — S3 Intelligent-Tiering suits data whose access pattern is unknown or changing. Here the pattern is known and static, so paying the monitoring and automation charge to discover it adds cost without benefit.
  • D — S3 Glacier Instant Retrieval is designed for archives that must come back in milliseconds. That capability costs more per GB than Deep Archive, and the requirement here does not need it.

Last verified: 2026-09-01

Question 23 clf-billing-basics-023

Easy · Choose one

How is Amazon EBS General Purpose SSD (gp3) volume storage billed?

  1. a On the number of read and write operations only
  2. b On the amount of storage provisioned, whether or not the volume is full
  3. c Only while the attached Amazon EC2 instance is in the running state
  4. d On the amount of data actually written to the volume
Show answer & explanation

Answer: B

Why B is correct

Amazon EBS bills on provisioned capacity. A 500 GB volume holding 20 GB of data is charged for 500 GB-months regardless of how empty it is, and the charge continues while the volume exists even if the attached instance is stopped. This is why rightsizing and deleting unattached volumes are standard cost-optimization actions, and it is a common source of unexpected charges for customers who assume storage is metered on consumption.

Why the others are wrong

  • A — For gp3, a baseline of 3,000 IOPS and 125 MiB/s is included in the volume price, and only provisioned performance above that baseline is charged separately. Storage capacity is always charged in addition.
  • C — Stopping the instance stops the instance charge, not the volume charge. An EBS volume continues to accrue storage charges until it is deleted.
  • D — Charging on data actually stored describes object storage such as Amazon S3, not block storage. EBS charges for the capacity you reserve.

Last verified: 2026-09-01

Question 24 clf-billing-basics-024

Easy · Choose one

On which dimensions does AWS Lambda charge for function usage?

  1. a The number of Amazon EC2 instances provisioned to run the function
  2. b The amount of source code stored in the function package, per GB-month
  3. c A flat monthly fee per function, regardless of how often it runs
  4. d The number of requests and the compute duration measured in GB-seconds
Show answer & explanation

Answer: D

Why D is correct

Lambda charges for the number of requests and for compute duration expressed in GB-seconds, which is the memory allocated to the function multiplied by the time it runs. Because no server is provisioned, an idle function costs nothing. AWS also provides a perpetual free allowance of 1 million requests and 400,000 GB-seconds per month, which makes low-volume event-driven workloads extremely inexpensive.

Why the others are wrong

  • A — Lambda is serverless. The customer never provisions or pays for instances; AWS manages the underlying compute entirely.
  • B — Function code is stored by the service and is not billed as a per-GB-month storage line item in the way described.
  • C — There is no per-function subscription fee. A function that is never invoked generates no duration or request charges.

Last verified: 2026-09-01

Question 25 clf-billing-basics-025

Intermediate · Choose one

A company moves log files to S3 Standard-Infrequent Access as soon as they are written, then deletes most of them after 10 days. Its S3 bill rises rather than falls. What is the most likely cause?

  1. a S3 Standard-IA applies a 30-day minimum storage duration charge, so objects deleted after 10 days are still billed for 30 days
  2. b S3 Standard-IA charges a fee each time an object is written, which exceeds the storage saving
  3. c S3 Standard-IA cannot be used with lifecycle rules, so the objects were duplicated into two storage classes
  4. d S3 Standard-IA replicates every object to a second AWS Region, doubling the storage charge
Show answer & explanation

Answer: A

Why A is correct

S3 Standard-IA carries a 30-day minimum storage duration charge. An object deleted or transitioned before 30 days is still billed as though it had been stored for the full 30 days, so short-lived data placed in an infrequent-access class costs more than leaving it in S3 Standard. Minimum duration charges also apply to S3 One Zone-IA at 30 days, S3 Glacier Instant Retrieval and Glacier Flexible Retrieval at 90 days, and S3 Glacier Deep Archive at 180 days, and they are a leading cause of lifecycle policies that backfire.

Why the others are wrong

  • B — Request charges do differ by storage class, but for a workload of this shape the dominant and documented effect is the minimum storage duration charge, not the per-request cost of writing.
  • C — Lifecycle rules work with S3 Standard-IA. Transitioning an object changes its storage class rather than creating a second copy.
  • D — S3 does not replicate to another Region unless the customer explicitly configures replication. Standard-IA stores objects across at least three Availability Zones within one Region.

Last verified: 2026-09-01

Question 26 clf-billing-basics-026

Intermediate · Choose one

A company has a large dataset whose access pattern is unpredictable and changes over time. It wants to reduce storage cost automatically without risking retrieval charges when access spikes. Which Amazon S3 storage class should it use?

  1. a S3 Intelligent-Tiering, which moves objects between access tiers automatically and charges no retrieval fees
  2. b S3 Standard-Infrequent Access, which is the lowest-cost class for data accessed a few times a year
  3. c S3 Glacier Flexible Retrieval, because objects can be restored in minutes when access increases
  4. d S3 One Zone-Infrequent Access, because it removes cross-Availability Zone replication cost
Show answer & explanation

Answer: A

Why A is correct

S3 Intelligent-Tiering exists precisely for unknown or changing access patterns. It monitors object access and moves objects between a Frequent Access tier, an Infrequent Access tier after 30 days without access, and an Archive Instant Access tier after 90 days, then moves them straight back on access. Critically, AWS charges no retrieval fees for Intelligent-Tiering, so an unexpected access spike does not produce a surprise bill. The only additional charge is a small monthly monitoring and automation fee per object.

Why the others are wrong

  • B — S3 Standard-IA charges a per-GB retrieval fee, so an access spike on data the company assumed was cold produces exactly the surprise charge it wants to avoid. It also carries a 30-day minimum storage duration.
  • C — Glacier Flexible Retrieval requires an explicit restore before objects can be read, imposes retrieval charges, and has a 90-day minimum storage duration, none of which suits unpredictable access.
  • D — One Zone-IA lowers cost by reducing durability protection to a single Availability Zone, and it still charges retrieval fees. It addresses a different trade-off entirely.

Last verified: 2026-09-01

Question 27 clf-billing-basics-027

Intermediate · Choose one

An application server in one Availability Zone communicates constantly with a database in a different Availability Zone in the same AWS Region. The team wants to reduce the resulting data transfer charges. Which statement should guide the redesign?

  1. a Traffic between Availability Zones is charged only on data leaving the source Availability Zone, so reversing the direction of the queries removes the charge
  2. b Traffic between Availability Zones in the same Region is charged in both directions, while traffic between resources in the same Availability Zone over private IPv4 addresses is not charged
  3. c Traffic between Availability Zones in the same Region is free, so the charges must be coming from somewhere else
  4. d Traffic between Availability Zones is free when both resources use public IPv4 addresses
Show answer & explanation

Answer: B

Why B is correct

AWS charges for data transfer between Availability Zones in the same Region, and the charge applies to both the inbound and outbound side of the transfer. Communication between resources in the same Availability Zone over private IPv4 addresses is not charged. That gives the architect a real cost lever, though it has to be weighed against resilience, since collapsing tiers into one Availability Zone removes the fault isolation that multi-AZ deployment provides.

Why the others are wrong

  • A — Reversing the direction changes nothing, because the charge applies to inbound and outbound traffic for the resources involved.
  • C — Cross-Availability Zone traffic within a Region is charged, so it is a legitimate and often significant line item for chatty application tiers.
  • D — Using public IPv4 or Elastic IP addresses makes matters worse, not better. Traffic routed through those addresses is charged even between resources in the same Region, because it leaves through the internet gateway.

Last verified: 2026-09-01

Question 28 clf-billing-basics-028

Intermediate · Choose one

What free allowance does AWS provide for data transfer out to the internet?

  1. a 1 TB per month for the first 12 months after the account is created
  2. b 100 GB per month, per AWS service, per AWS Region
  3. c 100 GB per month, aggregated across AWS services and AWS Regions
  4. d There is no free allowance for data transfer out to the internet
Show answer & explanation

Answer: C

Why C is correct

AWS provides 100 GB of data transfer out to the internet free each month, and the allowance is aggregated across AWS services and Regions rather than granted per service. The AWS China and AWS GovCloud (US) Regions are excluded. Beyond the free allowance, outbound transfer is charged on a tiered scale in which the per-GB rate falls as monthly volume rises.

Why the others are wrong

  • A — The allowance is a standing monthly benefit, not a 12-month introductory offer, and it is 100 GB rather than 1 TB.
  • B — Granting the allowance per service and per Region would multiply it many times over. AWS aggregates the 100 GB across services and Regions so an account receives it once per month.
  • D — There is a standing free allowance, which is why small workloads frequently show no data transfer out charges at all.

Last verified: 2026-09-01

Question 29 clf-billing-basics-029

Intermediate · Choose one

Which pair of Amazon S3 storage classes both return objects in milliseconds without requiring a restore operation?

  1. a S3 Glacier Flexible Retrieval and S3 Glacier Deep Archive
  2. b S3 Glacier Flexible Retrieval and S3 Standard-Infrequent Access
  3. c S3 Glacier Deep Archive and S3 One Zone-Infrequent Access
  4. d S3 Standard-Infrequent Access and S3 Glacier Instant Retrieval
Show answer & explanation

Answer: D

Why D is correct

Retrieval latency, not the word 'Glacier', is what separates these classes. S3 Standard-IA and S3 Glacier Instant Retrieval both deliver millisecond first-byte latency on a normal GET request with no restore step. Glacier Instant Retrieval simply prices storage lower and retrieval higher, with a 90-day minimum storage duration, for archives that are rarely read but must appear instantly when they are.

Why the others are wrong

  • A — Both of these require an explicit restore. Glacier Flexible Retrieval returns data in minutes to hours depending on the retrieval tier, and Deep Archive within 12 hours for Standard or 48 hours for Bulk.
  • B — S3 Standard-IA is millisecond-latency, but Glacier Flexible Retrieval is not, so the pair does not hold.
  • C — S3 One Zone-IA is millisecond-latency, but Deep Archive is the slowest class AWS offers, so the pair does not hold.

Last verified: 2026-09-01

Question 30 clf-billing-basics-030

Intermediate · Choose one

How does AWS charge for Amazon EBS snapshots after the first snapshot of a volume?

  1. a Each snapshot is a full copy of the volume and is charged for the entire provisioned volume size
  2. b Snapshots are incremental, so only the blocks that changed since the previous snapshot are charged
  3. c Snapshots are charged per snapshot operation, with no ongoing storage charge
  4. d Snapshots are free as long as they are stored in the same AWS Region as the volume
Show answer & explanation

Answer: B

Why B is correct

The first snapshot of an EBS volume is a full copy, but every subsequent snapshot stores only the blocks that changed since the previous one. Customers are billed for the actual data consumed rather than for the provisioned volume size multiplied by the number of snapshots. This is why a frequent snapshot schedule on a slowly changing volume is much cheaper than the snapshot count alone would suggest, and it is also why deleting one snapshot in a chain does not free as much storage as customers often expect.

Why the others are wrong

  • A — Only the first snapshot is a full copy. Charging for the full volume on every snapshot would make frequent backup schedules prohibitively expensive.
  • C — Snapshots incur an ongoing per-GB-month storage charge for the data they hold, so they must be lifecycle-managed to control cost.
  • D — Snapshot storage is charged regardless of Region. Copying snapshots to another Region adds data transfer charges on top.

Last verified: 2026-09-01