posted by B.B. on .
What is the ratio of the surface area for a pair of similar cylinders when the ratio of the heights is 1:3?
A) 1:4 B) 1:27 C) 1:9 D) 1:1
My answer is C) 1:9. Is this correct? Thanks.
I am not certain what you mean by similar?
Same diameter, different heights?
Same ratio changing height and diameter?
Are you considering surface area to include the ends?
If the same ratio is changing height and diameter is 1:3, then
SA=2PIr^2 + 2PIr(h) and if r and h are increased by three, then SA changes by a factor of nine.
So then the answer is it suppose to be 1:27 or 1:9?