Let the income of A = ₹ 9x and the income of B = ₹ 7x Also, the expenditure of A = ₹ 4y and the expenditure of B = ₹ 3y As per the condition, 9x – 4y = 200 ...(i) And 7x – 3y = 200 ...(ii) Solving eqn. (i) and (ii) we get x = 200 So, income of A = 9 × 200 = ₹ 1800