Question

The area of a smaller circle is one twenty-fifth of the area of a larger circle. What is the ratio of the radius of the larger circle to the radius of the smaller circle?

E. 1 : 25
F. 5 : 1
G. 1 : 5
H. None of the above

Answer 1

`f) \: r2 / r1 \: = 5 / 1`

Explanation:

`(a1)/(a2) = (1)/(25) = (\pi * (r1)^(2) )/(\pi * (r2)^(2))`

`{((r2)/(r1))}^(2) = 25`

`(r2)/(r1) = 5`