Let the incomes of A and B be Rs. 5x and Rs. 4x and their expenditures be Rs. 3y and Rs. 2y respectively. Hence, 5x – 3y = 1600 ...(i) 4x – 2y = 1600 ...(ii) Multiplying equation (i) by 2 and (ii) by 3 and subtracting, we get x=800 Hence, income of A = Rs. 5x = Rs. 5 × 800 = Rs. 4000