I would say 168 is the answer.
The answer is 100 if you want to get it correct
Answer:
_______________________________________________
1)
72
cm² / min. ;
_______________________________________________
2)
192
cm² / min. _______________________________________________Explanation:____________________________________________ Area of a circle: A =

r² ;
Rate of change of Area is: da/dt = 2

r (dr/dt) ;
Given: dr/dt = 3 cm / min.
______________________________________________________ Problem 1)____________________________________________________________dA/dt = 2

*(12 cm)*(3 cm/ min) =
72
cm² / min. ;
____________________________________________________________ Problem 2)____________________________________________________________dA/dt = 2

*(32 cm)*(3 cm/ min) =
192
cm² / min._____________________________________________________________
The equation is (assuming you meant the instead of two): T = 15c