With global cloud spending surging past $850 billion in data center commitments, cost optimization has never been more critical for Azure architects. The AZ-305 exam tests your ability to design cost-effective solutions. This is the first set (Questions 1–10) in our AZ-305 practice series. These AZ-305 practice questions focus on Azure cost optimization. They cover reserved instances, savings plans, tagging, budgets, and FinOps best practices.
Use these questions to sharpen your skills before exam day. Each one reflects a realistic scenario you might face as an Azure Solutions Architect.
Question 1: Choosing Between Reserved Instances and Savings Plans
Your company runs a mix of D-series and E-series VMs across three Azure regions. Workloads shift between VM families as demand changes. Management wants to reduce compute costs by at least 30% without locking into a single VM size or region.
A) Purchase 3-year Reserved Instances for D-series VMs in each region.
B) Purchase a 3-year Azure Savings Plan for Compute with an hourly commitment.
C) Move all workloads to B-series burstable VMs to lower baseline costs.
D) Use Azure Spot VMs for all production workloads.
👁 Reveal Answer
Correct Answer: B
Explanation: Azure Savings Plans for Compute apply automatically across VM families, regions, and operating systems. They save up to 65% on a 3-year term. This flexibility is ideal when workloads shift between VM series. Reserved Instances (A) lock you into a specific VM family, size, and region. They offer higher savings (up to 72%) but lack flexibility for shifting workloads. Burstable B-series VMs (C) are designed for variable workloads with low baseline CPU. They are not suitable for sustained compute. Spot VMs (D) can be evicted at any time. They are unsuitable for production workloads that require uptime guarantees.
Question 2: Enforcing Cost Allocation with Tags
A large enterprise deploys resources across 12 subscriptions. Finance needs to track spending by department. However, developers often forget to tag resources. You need a solution that prevents untagged resources from being created.
A) Create an Azure Budget alert that notifies the team when untagged resources appear.
B) Assign an Azure Policy with a “Deny” effect that requires a “Department” tag on all resources.
C) Use Azure Cost Management to filter by tag and send weekly reports.
D) Write a custom Azure Function that deletes untagged resources nightly.
👁 Reveal Answer
Correct Answer: B
Explanation: An Azure Policy with a “Deny” effect blocks resource creation when the required tag is missing. This enforces tagging at deployment time. It is the only option that prevents the problem proactively. Budget alerts (A) notify after the fact. They do not prevent untagged deployments. Cost Management filtering (C) helps with reporting but does nothing to enforce compliance. A custom Function (D) adds complexity and only catches the issue after resources already exist. Deleting resources retroactively also risks disrupting services.
Question 3: Right-Sizing Underutilized Virtual Machines
Azure Advisor flags that 40 VMs in your subscription average below 15% CPU utilization over the past 14 days. You need to reduce costs while maintaining performance during occasional spikes.
A) Shut down all 40 VMs and move workloads to Azure Functions.
B) Resize each VM to the next smaller SKU recommended by Azure Advisor.
C) Enable autoscaling on all 40 VMs using Virtual Machine Scale Sets.
D) Purchase Reserved Instances for the current VM sizes to lock in discounts.
👁 Reveal Answer
Correct Answer: B
Explanation: Azure Advisor analyzes usage patterns and recommends smaller SKUs that still meet performance needs. Resizing to a smaller SKU directly reduces hourly costs. It preserves the VM-based architecture. Moving everything to Functions (A) requires a complete application redesign. Not all workloads are suited for serverless. Autoscaling with VMSS (C) helps handle variable load. However, it does not reduce the cost of consistently underutilized individual VMs. Buying reservations at the current oversized SKU (D) locks in a discount on a resource you are already overpaying for. Right-size first, then consider reservations.
Question 4: Managing Budgets and Spending Alerts
Your organization wants to cap monthly Azure spending at $50,000 per subscription. Teams should receive warnings at 75% and 90% of the budget. Spending must stop automatically if the cap is reached.
A) Create an Azure Budget with action groups that disable resource groups at 100%.
B) Create an Azure Budget with alert thresholds at 75% and 90%, then use an action group that triggers an Azure Automation runbook to shut down non-essential resources at 100%.
C) Set a spending limit on each subscription in the Azure portal.
D) Use Azure Cost Management forecasts to predict overages and manually intervene.
👁 Reveal Answer
Correct Answer: B
Explanation: Azure Budgets support multiple alert thresholds and action groups. At 75% and 90%, the action group sends notifications. At 100%, it triggers an Automation runbook that shuts down non-essential resources. This provides both visibility and automated response. Disabling entire resource groups (A) is too aggressive. It could take down critical production services. Spending limits (C) are only available on certain subscription types like Free Trial or Visual Studio. They are not available on Enterprise or Pay-As-You-Go subscriptions. Manual intervention based on forecasts (D) is reactive. It depends on someone catching the alert in time.
Question 5: Selecting the Right Storage Tier
A healthcare application generates 500 GB of compliance reports monthly. Reports are accessed frequently during the first 30 days, rarely for the next 11 months, and must be retained for 7 years. You need the most cost-effective storage design.
A) Store all reports in the Hot tier for the entire retention period.
B) Store reports in Hot tier, then use a lifecycle management policy to move them to Cool after 30 days and Archive after 365 days.
C) Store all reports directly in the Archive tier from day one.
D) Use Azure Files Premium for the first 30 days, then move to Blob Storage Cool tier.
👁 Reveal Answer
Correct Answer: B
Explanation: Lifecycle management policies automate tier transitions based on age. Hot tier handles frequent access in the first 30 days. Cool tier (lower storage cost, higher access cost) covers months 2 through 12. Archive tier (lowest storage cost) covers the remaining 6 years. This approach minimizes cost at each stage. Keeping everything in Hot (A) wastes money on storage that is rarely accessed. Storing directly in Archive (C) makes the first 30 days impractical. Archive retrieval takes hours and incurs high access fees. Azure Files Premium (D) is designed for high-performance file shares. It is expensive and unnecessary for blob-based compliance reports.
Question 6: Optimizing Costs with Azure Hybrid Benefit
Your company migrates 200 Windows Server VMs from on-premises to Azure. The company holds active Software Assurance licenses for all servers. You need to minimize Azure compute costs during migration.
A) Deploy VMs using pay-as-you-go pricing and apply for a Microsoft volume discount.
B) Deploy Linux VMs to avoid Windows licensing costs entirely.
C) Apply Azure Hybrid Benefit to the VMs to use existing Windows Server licenses on Azure.
D) Purchase 3-year Reserved Instances without Azure Hybrid Benefit.
👁 Reveal Answer
Correct Answer: C
Explanation: Azure Hybrid Benefit lets you use existing on-premises Windows Server licenses (with Software Assurance) on Azure VMs. This removes the Windows license cost from the VM price. Savings can reach up to 40% on Windows VMs. You can also combine it with Reserved Instances for up to 80% total savings. Pay-as-you-go (A) does not leverage existing licenses. Volume discounts require separate negotiation and do not apply automatically. Switching to Linux (B) changes the operating system. It requires application compatibility testing and may not be feasible. Reserved Instances alone (D) reduce compute cost but still charge for the Windows license. Hybrid Benefit should be applied first.
Question 7: Handling Fault-Tolerant Workloads with Spot VMs
A data analytics team runs nightly batch jobs that process large datasets. The jobs can be restarted if interrupted. Average processing time is 4 hours. The team wants to minimize compute costs for these jobs.
A) Use Standard D-series VMs with pay-as-you-go pricing.
B) Use Azure Spot VMs with an eviction policy set to Deallocate.
C) Use Azure Container Instances with always-on containers.
D) Use Reserved Instances for the D-series VMs used nightly.
👁 Reveal Answer
Correct Answer: B
Explanation: Azure Spot VMs offer discounts of up to 90% compared to pay-as-you-go pricing. They are ideal for workloads that tolerate interruptions. Batch jobs that can restart fit this model perfectly. The Deallocate eviction policy preserves the VM configuration for easy restart. Standard pay-as-you-go (A) works but is the most expensive option for a workload that can tolerate interruptions. Container Instances (C) bill per second of use but do not offer the deep discounts of Spot pricing. Reserved Instances (D) provide savings for always-on workloads. Nightly batch jobs only run 4 hours per day. Reservations would be wasted for the other 20 hours.
Question 8: Designing a FinOps Governance Model
A multinational company with 50 Azure subscriptions across 8 departments has no cost visibility. Each department manages its own subscriptions. Leadership wants a centralized FinOps practice that provides cost transparency, enforces accountability, and reduces waste by 20%.
A) Consolidate all subscriptions into a single subscription and assign department-level resource groups.
B) Implement Management Groups with Azure Policy for tagging, create Azure Budgets per department, and use Cost Management + Billing for cross-subscription reporting.
C) Give each department a fixed monthly Azure credit and let them manage spending independently.
D) Migrate all workloads to a single resource group and use Azure Monitor to track costs.
👁 Reveal Answer
Correct Answer: B
Explanation: Management Groups provide a hierarchy above subscriptions for governance at scale. Azure Policy enforces consistent tagging across all 50 subscriptions. Budgets per department provide spending guardrails with alerts. Cost Management + Billing offers cross-subscription dashboards. Together, these tools deliver the visibility, accountability, and automation needed for FinOps. Consolidating into one subscription (A) removes the isolation that different departments need. It creates a management bottleneck. Fixed credits (C) do not provide visibility or governance. Departments may hit limits and lack tools to optimize. A single resource group (D) is impractical at this scale. Azure Monitor tracks performance metrics, not cost details. Cost Management is the correct tool for financial reporting.
Question 9: Optimizing Costs for Dev/Test Environments
Your organization runs 15 development and testing environments in Azure. Developers work Monday through Friday, 8 AM to 6 PM. The environments sit idle on nights and weekends. Management wants to cut dev/test costs by at least 50%.
A) Purchase 1-year Reserved Instances for all dev/test VMs.
B) Use Azure DevTest Labs with auto-shutdown policies and start/stop schedules.
C) Move all dev/test workloads to Azure Spot VMs.
D) Downgrade all VMs to the B1s burstable tier permanently.
👁 Reveal Answer
Correct Answer: B
Explanation: Azure DevTest Labs provides auto-shutdown and scheduled start/stop policies. VMs deallocate during nights and weekends, eliminating compute charges for idle hours. Dev/test environments run roughly 50 hours per week out of 168 total. This approach directly targets the waste. Reserved Instances (A) save on hourly cost but still charge for hours when VMs sit idle. Spot VMs (C) risk eviction during active development, which disrupts productivity. Permanently downgrading to B1s (D) may not provide enough compute for meaningful testing.
Question 10: Consolidating Cost Visibility Across Subscriptions
A company acquired two subsidiaries, each with its own Azure Enterprise Agreement and billing account. Leadership needs a single dashboard showing total Azure spend across all three organizations. They also need chargeback reports by business unit.
A) Export cost data from each billing account to a shared Storage Account and build reports in Power BI.
B) Merge all subscriptions into one Enterprise Agreement and use Azure Cost Management.
C) Use Azure Lighthouse to manage cross-tenant resources and view costs centrally.
D) Create a billing scope at the Microsoft Customer Agreement level that spans all tenants.
👁 Reveal Answer
Correct Answer: A
Explanation: Exporting cost data to a shared Storage Account and visualizing in Power BI is the recommended approach for cross-billing-account cost analysis. Azure Cost Management natively supports exports in CSV format. Power BI connects directly to the storage and supports custom chargeback models. Merging into one EA (B) requires contract negotiation and may not be feasible due to legal or organizational constraints. Azure Lighthouse (C) provides cross-tenant management but does not consolidate billing data across separate Enterprise Agreements. A single MCA billing scope (D) cannot span independent tenants with separate Enterprise Agreements.
Study Tips for AZ-305 Cost Optimization
- Right-size first, reserve second. Always optimize VM sizes based on Azure Advisor before committing to reservations or savings plans.
- Know the discount hierarchy. Spot VMs offer the deepest discounts (up to 90%) but with eviction risk. Reserved Instances save up to 72%. Savings Plans save up to 65% with more flexibility. Azure Hybrid Benefit stacks on top of either.
- Lifecycle policies are your friend. Automate storage tier transitions to avoid paying Hot prices for Archive-worthy data.
- Tags drive accountability. Azure Policy with “Deny” is the only way to enforce tagging at deployment time. Reports and alerts catch problems after the fact.
- FinOps is a recurring exam theme. Expect case-study questions that combine budgets, tagging, reserved instances, and governance into a single scenario. Think holistically.
Keep practicing and reviewing these concepts. Cost optimization appears in nearly every AZ-305 case study. For more Azure practice questions, explore our Microsoft certification collection. For the official exam objectives, visit the AZ-305 study guide on Microsoft Learn.