The ratio of incomes of two persons is 9 : 7 and the ratio of their ex

1.	The ratio of incomes of two persons is 9 : 7 and the ratio of their expenditures is 4 : 3. If each of them manages to save Rs. 2000 per month, find their monthly income.
Answer» Given ratio of incomes of two persons = 9 : 7 So let the incomes of each = Rs. 9x and Rs. 7x and ratio of expenditures = 4 : 3 So let the expenditures of each = 4y and 3y then earnings of each = (income – expenditure) of each ⇒ 9x – 4y = Rs. 2000 and 7x – 3y = 200 ∴ 9x – 4y = 7x – 3y = 2000 ⇒ 9x – 7x = 4y – 3y ⇒ y = 2x now putting y = 2x in 9x – 4y = 2000 we get 9x – 4(2x) = 2000 ⇒ x = 2000 ∴ Income of each = 9x = 9(2000) = 18000 and 7x = 7(2000) = 14,000

The ratio of incomes of two persons is 9 : 7 and the ratio of their expenditures is 4 : 3. If each of them manages to save Rs. 2000 per month, find their monthly income.

Answer»

Given ratio of incomes of two persons = 9 : 7

So let the incomes of each = Rs. 9x and Rs. 7x and ratio of expenditures = 4 : 3

So let the expenditures of each = 4y and 3y then earnings of each = (income – expenditure) of each

⇒ 9x – 4y = Rs. 2000 and 7x – 3y = 200

∴ 9x – 4y = 7x – 3y = 2000

⇒ 9x – 7x = 4y – 3y

⇒ y = 2x

now putting y = 2x in 9x – 4y = 2000

we get 9x – 4(2x) = 2000 ⇒ x = 2000

∴ Income of each = 9x = 9(2000) = 18000 and 7x = 7(2000) = 14,000