If the income of X is 20% more than that of Y, and the income of Y is 25% less than that of Z, then the incomes of X, Y and Z are in which of the following ratios?

A18 : 15 : 20 ✓ Correct

B18 : 15 : 10

C18 : 10 : 15

D18 : 12 : 15

Correct answer: (A) 18 : 15 : 20

Explanation

The ratio X : Y : Z is 18 : 15 : 20.

X is 20% more than Y, so X = 1.2Y = 6Y/5.

Y is 25% less than Z, so Y = 0.75Z = 3Z/4.

Then X = 6/5 x 3/4 Z = 9Z/10, giving X : Y : Z = 9/10 : 3/4 : 1.

Multiplying through by 20 gives 18 : 15 : 20.

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