Carcass wrote:

A certain recipe makes enough batter for exactly 8 circular pancakes that are each 10 inches in diameter. How many circular pancakes, each 5 inches in diameter and of the same thickness as the 10-inch pancakes, should the recipe make?

(A) 4

(B) 16

(C) 24

(D) 32

(E) 40

Here,

The thickness is same in both the cases

so Radius in the 1st case = 5 inches

and Radius in the 2nd case = \(\frac{5}{2} = 2.5 inches\)

Let us take no. of pancakes can be prepared from 5 inch diameter = N

Therefore ,

\({N * \pi * (2.5)^2 = 8 * \pi * 5^2}\)

or, \(N = \frac{8.25}{6.25} = 32\)

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