A and B are two circles. The radius of A is 5 times as large as the radius of B. What is the ratio between the areas of the circles? Choose the correct choice from the following answers.
A) 1 : 8 .
B) 1 : 2 .
C) 1 : 4 .
D) 1 : 25 .
E) 1 : 6 .

Rationale: given : the radius of a is 5 times as large as the radius of b . = > r ( a ) = 5 r ( b ) . the radius are in ratio of 1 : 5 thus the area will be in the ratio of square of radius . 1 : 25 . hence d .
Answer: D