Question

The ratio of incomes of two persons is 11:7and ratio of their expenditures is 9:5. If each of them manages to save ₹400 per month , find their monthly incomes.

Answer 1

The explanation is as follows.

Consider the monthly income of both be 11x and 7x and expenditure be 9y and 5y.

According to the question,

11x - 9y = 400

7x - 5y = 400

by using elimination method,

77x - 63 y = 2800 -------(1)

77x - 55y = 4400 ----------(2)

Substract (2) from (1) we get

77x -77x -63y +55y = 2800 - 4400

-8 y = -1600

y = 1600/8 = 200

then x = 1400/7 = 200

∴ the incomes of both are,11x = Rs.2200 and 7x = Rs.1400 .

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