Question

The area of circle B is 121 times greater than the area of circle A. The radius of circle B is 44. What is the radius of circle A?

A) 2.75

B) 4

C) 44

D) 88

Answer 1

Formula:

`\bigg( (radius_1)/(radius_2) \bigg)^2 = (area_1)/(area_2)`

Plug in the values:

`\bigg( (r)/(44) \bigg)^2 = (1)/(121)`

Simplify LHS:

`(r^2)/(1936) = (1)/(121)`

Multiply by 1936 on both sides:

`r^2 = (1936)/(121)`

Simplify RHS:

`r^2 = 16`

Square root both sides:

`r = 4`

Answer: The radius is 4 units. (Answer B)