diff --git a/practice-exam/practice-exam-17.md b/practice-exam/practice-exam-17.md
index 3a560ab..5b4d332 100644
--- a/practice-exam/practice-exam-17.md
+++ b/practice-exam/practice-exam-17.md
@@ -146,13 +146,12 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: D
+    Correct Answer: C
 
     Explanation:
-    - AWS manages dozens of compliance programs in its infrastructure.
-    - This means that segments of your compliance have already been completed.
+    - AWS allows you to access as much or as little capacity as you need, and scale up or down as required with only a few minutes’ notice
 
-    Reference: <https://docs.aws.amazon.com/whitepapers/latest/aws-overview/security-and-compliance.html>
+    Reference: <https://docs.aws.amazon.com/whitepapers/latest/aws-overview/six-advantages-of-cloud-computing.html>
 
     </details>
 
@@ -183,9 +182,11 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: BC
+    Correct Answer: AD
 
-    Explanation: <https://aws.amazon.com/getting-started/tutorials/continuous-deployment-pipeline/>
+    Explanation:
+    - EBS -> automates deploying code and provisioning infrastructure
+    - CloudFormation -> Use templates to deploy code and infrastructure
 
     </details>
 
@@ -216,7 +217,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: AC
+    Correct Answer: AB
 
     Explanation: <https://aws.amazon.com/blogs/apn/the-5-pillars-of-the-aws-well-architected-framework/>
 
@@ -365,7 +366,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: D
+    Correct Answer: B
 
     Explanation: <https://aws.amazon.com/premiumsupport/knowledge-center/ec2-instance-hour-billing/>
 
@@ -637,7 +638,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: BC
+    Correct Answer: AC
 
     </details>
 
diff --git a/practice-exam/practice-exam-20.md b/practice-exam/practice-exam-20.md
index d3072e9..6c1715b 100644
--- a/practice-exam/practice-exam-20.md
+++ b/practice-exam/practice-exam-20.md
@@ -589,7 +589,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: CD
+    Correct Answer: BC
 
     </details>
 
diff --git a/practice-exam/practice-exam-21.md b/practice-exam/practice-exam-21.md
index 219366a..c8bfa1b 100644
--- a/practice-exam/practice-exam-21.md
+++ b/practice-exam/practice-exam-21.md
@@ -106,7 +106,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     </details>
 
-8. Under the AWS shared responsibility model, which of the following are customer responsibilities? (Choose two.)   
+8. Under the AWS shared responsibility model, which of the following are customer responsibilities? (Choose two.)
     - A. Setting up server-side encryption on an Amazon S3 bucket
     - B. Amazon RDS instance patching
     - C. Network and firewall configurations
@@ -691,7 +691,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: B
+    Correct Answer: D
 
     </details>
 
diff --git a/practice-exam/practice-exam-22.md b/practice-exam/practice-exam-22.md
index f4a0338..bd55ae3 100644
--- a/practice-exam/practice-exam-22.md
+++ b/practice-exam/practice-exam-22.md
@@ -63,7 +63,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: A
+    Correct Answer: D
 
     </details>
 
@@ -160,7 +160,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: CD
+    Correct Answer: CE
 
     </details>
 
@@ -306,10 +306,12 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: D
+    Correct Answer: BD
 
     Explanation: <https://aws.amazon.com/blogs/startups/large-scale-disaster-recovery-using-aws-regions/>
 
+    Option D increased complexity and cost.
+
     </details>
 
 26. A company has a 500 TB image repository that needs to be transported to AWS for processing. <br/> Which AWS service can import this data MOST cost-effectively?
@@ -466,7 +468,7 @@ If this practice exam has been helpful to you please share it with others and re
     </details>
 
 37. What is a characteristic of Convertible Reserved Instances (RIs)?
-    - A. Users can exchange Convertible RIs for other Convertible RIs from a different instance family.
+    - A. Users can exchange Convertible RIs for other Convertible RIs from a different instance family with an equal or higher value than the Convertible Reserved Instances that you are exchanging.
     - B. Users can exchange Convertible RIs for other Convertible RIs in different AWS Regions.
     - C. Users can sell and buy Convertible RIs on the AWS Marketplace.
     - D. Users can shorten the term of their Convertible RIs by merging them with other Convertible RIs.
diff --git a/practice-exam/practice-exam-23.md b/practice-exam/practice-exam-23.md
index 6fe2d2b..65bfd4a 100644
--- a/practice-exam/practice-exam-23.md
+++ b/practice-exam/practice-exam-23.md
@@ -165,7 +165,7 @@ If this practice exam has been helpful to you please share it with others and re
 
     <details markdown=1><summary markdown="span">Answer</summary>
 
-    Correct Answer: A
+    Correct Answer: C
 
     Explanation: <https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/awsaccountbilling-aboutv2.pdf>
 
diff --git a/practice-exam/practice-exam-9.md b/practice-exam/practice-exam-9.md
index 78c42c1..aa7719e 100644
--- a/practice-exam/practice-exam-9.md
+++ b/practice-exam/practice-exam-9.md
@@ -432,7 +432,7 @@ If this practice exam has been helpful to you please share it with others and re
     - D. They do not require the customer to optimize instance type or size selections.
 
     <details markdown=1><summary markdown='span'>Answer</summary>
-      Correct answer: C
+      Correct answer: B
     </details>
 
 43. Which services can be used across hybrid AWS Cloud architectures? (Select TWO)