If carton containing a dozen mirrors is dropped, which of the following cannot be the ratio of broken mirrors to unbroken mirrors?

Greater number = 420 x (4/7) = 240

Ratio = 1/2 : 1/3 : 1/4 = 6 : 4 : 3
? share of third friend = Rs. (624 x 3/13)
= Rs. 144

Let the number of boys and girls be x and y respectively. Then
From question, (x - y ) = 12% of (x + y)
? x/y = 3/25 (x + y )
? 25x - 25y = 3x + 3y
? 22x = 28y
? x / y = 28 / 22 = 14 / 11

Let the side of the square be 'a' and let the radius of the circle be 'r'
Then, a² = ?r²
? a² / r² = ?
? a / r = ??
? a : r = ?? : 1

? 18 x 18 = y²
? y = ?144 = 12

For dividing 64 into two whole number, the sum of the terms of the ratio must be factor of 64, so they cannot be in the ratio 3 : 4.

Less length, less weigth
From question, 13 : 6 : : 23.4 : W
? 13 x W = 6 x 23.4
? W = (6 x 23.4) /13 = 10.8 kg

Let 0.8 : 0.2 : : 0.2 : N
Then 0.8 x N = 0.2 x 0.2
? N = ( 0.2 x 0.2) / 0.8 = 0.04 / 0.08 = 4/80 = 0.05

Mean proportional = ?0.32 x 0.02
= ?0.0064 = 0.08

Let 0.2 : 0.12 : : 0.3 : N
? 0.2 x N = 0.12 x 0.3
? N = (0.12 x 0.3) / 0.2 = 0.18