The monthly incomes of two friends Kiran and Mahesh, are in the ratio 5 : 7 respectively and each of them saves ₹78000 every month. If the ratio of their monthly expenditure is 1 : 3, find the monthly income of Kiran(in ₹).

Correct option is B

Given:

The monthly incomes of Kiran and Mahesh are in the ratio 5 : 7.

Both Kiran and Mahesh save ₹78,000 every month.

The ratio of their monthly expenditures is 1 : 3.

Formula Used:

Income = Expenditure + Savings

Solution:

Let Kiran's monthly income be 5x and Mahesh's monthly income be 7x, where x is the common multiplier.

Let Kiran's monthly expenditure be E$$_k$$​ and Mahesh's monthly expenditure be E$$_m.$$​​

Kiran's income = 5x

Kiran's savings = ₹78,000

Kiran's expenditure = $$E_k$$​​

So, Kiran's income = Kiran's expenditure + Kiran's savings:

5x =$$E_k$$​+ 78,000

Therefore:

​$$E_k = 5x - 7$$​8,000

Mahesh's income = 7x

Mahesh's savings = ₹78,000

Mahesh's expenditure =$$E_m$$​​

So, Mahesh's income = Mahesh's expenditure + Mahesh's savings:

7x =$$E_m$$​ + 78,000

Therefore:

​$$E_m = 7x -$$​78,000

Using the ratio of their expenditures:
The ratio of their expenditures is given as 1 : 3. Therefore:

​$$\frac{E_k}{E_m} = \frac{1}{3}$$​

​$$\frac{5x - 78,000}{7x - 78,000} = \frac{1}{3}$$​

3(5x - 78,000) = 1(7x - 78,000)

15x - 234,000 = 7x - 78,000

15x - 7x = 234,000 - 78,000

8x = 156,000

x $$= \frac{156,000}{8}$$​= 19,500

Kiran's income = 5x = 5 × 19,500 = ₹97,500
The monthly income of Kiran is ₹97,500.