Question

Please help don't guess.

Answer 1

The easy way to do this is:

Since the radius of the second circle is exactly 6 times the radius of the first circle, you could just multiply the circumference by 6:

9.42 x 6 = 56.52! But let's double-check.

9 x 2 = 18 So, the diameter is 18.

18 x 3.14 = 56.52! So, 56.52 is the correct answer!

Answer 2

Remark

The formula you should be using is

C = k*r because this is a variation question. There are ways of doing this without solving for k, but it is a good idea to solve for k first.

Givens

C = 9.42

r = 1.5

k = ??

K =

C = k*r

9.42 = k * 1.5

k = 9.42/1.5

k = 6.28 which is what it should be given that pi = 3.14. But you must check.

r = 9

C = k*r

C = 6.28 * 9

C = 56.52 which rounded = 57 to the nearest inch

57 Answer