I am having issues with question 2. But for context Question 1 is needed.

Questions #1 and #2 are about the following situation.

A telephone call center uses three customer service representatives (CSRs) during the 8:30 am to 9 am period. The standard service rate is 3.0 minutes per telephone call per CSR.

If the target labor utilization rate is 80 percent, how many calls should these three CSRs handle during this half-hour period?

The Answer is 24 calls

Question 2 asks

This questions is about the situation described in Question #1.

If the number of CSRs increased from 3 to 4 and the standard service rate decreased to 3.5 minutes, how many more calls would the call center be able to handle between 8:30 and 9 am?

6.6 more calls

7.7 more calls

8.6 more calls

9.4 more calls

10.3 more calls