The monthly incomes of two friends Rupesh and Manjit, are in the ratio 5 : 7 respectively and each of them saves ₹84000 every month. If the ratio of their monthly expenditure is 2 : 3, find the monthly income of Rupesh(in ₹).

Correct option is A

Given:

Ratio of incomes (Rupesh : Manjit) = 5 : 7

Savings of both = ₹84000 each

Ratio of expenditures = 2 : 3

Formula Used:
Income = Expenditure + Saving

Solution:
Let Rupesh’s income = 5x, Manjit’s income = 7x
Let Rupesh’s expenditure = 2y, Manjit’s expenditure = 3y

So,
5x – 2y = 84000 …(i)
7x – 3y = 84000 …(ii)

Multiply (i) by 3 

15x – 6y = 252000
Multiply (ii) by 2

14x – 6y = 168000

Subtract:

(15x – 14x) = (252000 – 168000)
x = 84000

Rupesh’s income = 5x = 5 × 84000 = 420000