MathRevolution wrote:

There are two circle-shaped pizzas. The diameter of the smaller pizza is 10 and the larger pizza’s area is 2 times of the smaller pizza’s area, what is the diameter of the larger pizza, in whole number?

A. 12

B. 15

C. 18

D. 20

E. 25

*An answer will be posted in 2 days.

Area of smaller pizza = (\(\pi\)\(10^2\))/ 4, where 10 is the dia of smaller circle.

Area of bigger pizza = twice of area of smaller pizza = (\(\pi\)\(10^2\))/

2if r is the radius of bigger pizza.

\(\pi\)\(r^2\) = (\(\pi\)\(10^2\))/

2\(r^2\) = 50

r = \(\sqrt{50}\)

diameter = 2r = 10\(\sqrt{2}\)

dia = 14.1416.

nearest value should have been 14. It is not given. So we will choose 15.

B is the answer.