I'm stuck pls ! #13 i'm not sure what to do pls !

I'm being volume of cylinder with 13 in. radius and 30 in height answer choices in pic

Could somebody me with this radical simplification?

Question 1 of 10 2 points different groups of 50 graduates of an engineering school were asked the starting annual salary for their first engineering job after graduation, and the sampling variability was low. if the average salary of one of the groups was $65,000, which of these is least likely to be the average salary of another of the groups? o a. $64,000 o b. $65,000 o c. $67,000 o d. $54,000