Answer:
the volume has grown 25 times
Explanation:
the formula to megure (sorry for my bad english) is 1/3 x π x r2 x h
now, this would be 1/3 x π x 4 x 7 = 29,32
if u multiplied the radius and the height by 5, you would get;
1/3 x π x 20 x 35 = 733,03
now to see how much the volume has changed, you devide one on another;
733,03/29,32 = 4/100 = 25
and 25 is 5^2