Answer :

Kireeth
Hank is 9 years old. Explanation - What I did is I made a chart, and the categories were Sam and Hank. Then all I did was add 5 to Sam's age and added 3 to Hank's age. I repeated this until the sum of the ages equaled 24.
xXxGirxXx
5:3      :Sum is: 8

10:6     :Sum is: 16

15:9     :Sum is: 24

The ration is of Sam to Hank, so Sam would be the first number, and Hank would be the second number.

Hank is 9 years old.