Question

 The ratio of income of two persons is 11:7 and the ratio of their expenditures is 9:5 . If each of them manages to save Rs. 400 per month then the monthly income of first per​

Answer 1

Answer:

1000

Step-by-step explanation:

Incomes are in the ratio of 11:7.

Hence, let the incomes of the first and second person be 11x and 7x

Expenditures are in the ratio 9:5.

Hence, let the expenditures of the first and second persons be 9y and 5y

Saving = Income - Expenditure

For first person, saving = 11x - 9y

For second person, saving = 7x - 5y

ATQ, each of the two persons saves Rs.400

=> 11x - 9y = 400 .....(i)

=> 7x - 5y = 400 ......(ii)

Multiplying (i) by 5 and (ii) by 9, we get:

55x - 45y = 2000 ........(iii)

63x - 45y = 3600 ........(iv)

Subtracting (iv) from (iii), so as to eliminate variable "y", we get:

-8x = -1600

=> x = 200

Substituting for "x" in (i), we get:

11*200 - 9y = 400

2200 - 9y = 400

9y = 1800

=> y = 200

For first person:

Income = 11x = 11*200 = 2200

Expenditure = 9y = 9*200 = 1800

For second person:

Income = 7x = 7*200 = 1400

Expenditure = 5x = 5*200 = 1000