Question

The volume of a cylinder with a radius of 2 feet and a height of 4 feet is 50.2 feet^3.
The volume of a cylinder with a radius of 4 feet and a height of 8 feet is 401.9 feet^3.
The volume of a cylinder with a radius of 6 feet and a height of 12 feet is 1356.5 feet^3.
If the radius and height are doubled, the volume will be _____ times as large.

A. 27
B. 8
C. 2
D. 4

Wouldn't the answer be 4?

Answer 1

What does doubled mean Johnny? If you double something how much bigger is it going to get?

Answer 2

Multiplied by 2?

Answer 3

Yes johnny

Answer 4

No Abbies

Answer 5

yes Johnny when you double something your multiplying it by 2

Answer 6

since V = pi(r^2)h
if we double r and h
new V = pi(2r)^2(2h)
= 8pi r^2 h

so it increased 8 times

or, since they gave you the volume after doubling in the second sentence, just divide
401.9/50.2 = 8.0059... or 8 times

or

volume of similar objects varies directly with the cube of their sides
2^3 : 4^3
= 8 : 64
= 1 : 8

Answer 7

Thanks for the help Reiny