You want to read 420 items of 5KB each from a DynamoDB table every minute using strong consistency read. How many RCUs will you need to provision your DynamoDB table with?

Answer options:

A.10
B.14
C.28
D.12

Correct Answer: B
1 RCU provides 4KB read per second for a strong consistency model.
Items to read every second: 420/60 = 7
To read one item, we need: 5/4 = 1.25, rounding UP to the nearest whole number will be 2. Hence, we require 2 RCUs to read one item.
Total RCUs required: 2*7 = 14
Option A, C and D are incorrect since they are not the required RCUs to perform the above operation.
Reference: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadWriteCapacityMode.html