Solution:Expense for 3 months = 3 *2200 = ₹ 6600Expense for next 4 months = 4* 2500= ₹ 10200
Expense for next 5 months = 5 * 3120 = ₹ 15600
Total expense for 12 months = 6600 + 10200 + 15600 = ₹ 32400
Total saving = ₹ 1260
Total income = 32400 + 1260
= ₹ 33660
Income in one month = 33660/12 = ₹ 2805