Question

The ages of Hari and Harry are in the ratio 5:7. Four years from now the ratio of their ages will be 3:4. Find their present ages

Answer 1

Hari is 20; Harry is 28

Explanation:

The ratio in 4 years is equivalent to the ratio 6:8, which has each of the original ratio unit numbers increased by 1. That means each of those ratio units stands for 4 years, and the present ages are ...

Hari: 5·4 = 20

Harry: 7·4 = 28

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Conventional method of solution

If you like, you can write equations for the ages of Hari (x) and Harry (y):

x/y = 5/7

(x+4)/(y+4) = 3/4

These can be solved a variety of ways. For some methods, it may be useful to write them in standard form:

• 7x -5y = 0
• 4x -3y = -4

These have solution (x, y) = (20, 28).