Let the monthly income of A and B be 3x and 4x And the monthly expenditures be 2y and 3y Saving = income – expenditure 4000 = 4x – 3y ...1) Similarly, 4000 = 3x – 2y ...2) From 2 × (1) – 3 × (2) 8000 – 12000 = 8x – 9x x = 4000 The income of B = 4x = 16000 ∴ The income of B is 16000. Short method,