Tips & Tricks Calculation: Let the monthly income of Pawan & Sunil be 4x & 3x respectively Let the monthly expenditure of Pawan & Sunil be 3y & 2y respectively According to the question, ⇒ 4x – 3y = 4000 ...i) ⇒ 3x – 2y = 6000 ...ii) ⇒ (i) × 2 – (ii) × 3 ⇒ 8x – 6y – (9x – 6y) = 8000 – 18000 ⇒ -x = -10000 ⇒ x = 10000 Sum of their monthly income = 4x + 3x = 7x = Rs. 70000