Question

An article can be bought by paying Rs. 28,000 at once or by making 12 monthly installments. If the first installment paid is Rs. 3,000 and every other installment is Rs. 100 less than the previous one, find:

1. amount of installments paid in the 9^th month.
2. total amount paid in the installment scheme.

Answer 1

Number of installments = n = 12

First installment = a = Rs. 3000

Depreciation in installment = d = –100

i Amount of installment paid in the 9^th month 

= t₉

= a + 8d

= 3000 + 8 × (–100)

= 3000 – 800

= Rs. 2200

ii. Total amount paid in the installment scheme

= S₁₂

= `12/2 [2 xx 3000 + 11 xx (-100)]`

= 6[6000 – 1100]

= 6 × 4900

= Rs. 29,400