What number should be subtracted from each of the number 23, 30, 57 and 78 so that the remainders are in proportion?

A - 4

B - 3

C - 6

D - 7

Answer : C

Explanation

Proportion says that two ratios (or fractions) are equal. Example: 1/3 = 2/6.

If y-x/x = 3/8. Find y:x

A - 11 : 8

B - 8 : 11

C - 8 : 5

D - 5 : 8

Answer : A

Explanation

x = 8, y-x = 3, so y = 11, y : x = 11 : 8.