We know that, Average = Sum of entities/number of entities His total expenditure in 1 year = (7 × 1300) + (5 × 1200) = Rs. 15100. His total savings = Rs. 2900. ∴ His annual total earning = Rs. 15100 + Rs. 2900 = 18000. ∴ His Monthly income = Rs. 18000/12 = 1500. ∴ His monthly income = Rs. 1500.