Let, the incomes of A and B are Rs. 7x and 5x and their expenditures are Rs. 5y and 3y respectively, then 7x–5y=5x–3y=1600 ⇒7x–5y=5x–3y ⇒2x=2y ⇒y=x Now, 7x–5y=1600 ⇒7x–5x=1600 ⇒2x=1600 ⇒x=800 Thus, their incomes are: 7x=7×800=Rs.5600 5x=5×800=Rs.4000