Question

Deepa has to buy a scooty by making 17 monthly installment as below.
1st month-3625,
2nd month-3425
3rd month-3225 and so on.
(i)find amount of 8th installment.
(ii)Find the amount of last instalment
(iii)Total amount that she need to pay.

Answer 1

6th month

For 6th installment find the common difference which is 200.

For sum of 15 installments use the Sn formula

Sn = n/2 [2a+(n-1)d]