Shamshad Ali buys a scooter for Rs 22000. He pays Rs. 4000 cash and agrees to pay the balance in annual instalment of Rs 1000 plus 10% interest on the unpaid amount. How much will the scooter cost him?
Original cost of scooter = Rs. 22000
Amount paid in cash = Rs. 4000
Amount to be paid in instalments = Rs. 18000
Let a denote the first instalment
a = 1000 + 10% interest on unpaid amount
= Rs .
a = Rs. 2800
2nd instalment = 
Similarly, 3rd instalment = Rs. 2600
∴ Various instalments are Rs. 2800, Rs. 2700, Rs. 2600.........
Amount paid in instalments = Rs. 2800 + Rs . 2700 + Rs . 2600 + ......+ Rs. 1100
= Rs . 
= Rs. 9[5600 - 1700] = Rs. 9(3900) = Rs. 35100
Actual amount by Hari = Rs. [35100 + 4000] = Rs 39100
