Question

Raghu wish to buy a laptop . he can buy it by paying ₹ 40,000 cash or by giving it in 10 installments as ₹ 4800 in the first month,₹4750 in the second month,₹ 4700 in the third month and so on . if he pays the money in this fashion, find 1) total amount paid in 10 installments?
2) how much extra amount that he has to pay than the cost?

Answer 1

Answer:

Total amount paid in 10 installments is Rs. 45750 and Extra amount he has to pay is Rs. 5750.

Step-by-step explanation:

Given:

Cost of Laptop = Rs. 40000

He can pay totally in cash or by 10 installments.

Installments are Rs. 4800 , Rs. 4750 , Rs. 4700 , so on ...

To find: total amount paid in 10 installments and extra amount he has pay.

Clearly Installments are forming an AP with first term , a = 4800 and common difference, d = 4750 - 4800 = -50

Using formula of sum of n term, $S_n=\frac{n}{2}(2a+(n-1)d)$

Total amount in 10 installments = $S_{10}=\frac{10}{2}(2(4800)+(10-1)(-50))$

                                                    $=5(9600+(-450))$

                                                    $=5(9150)$

                                                    $=Rs.\:45750$

Extra amount he pay = 45750 - 40000 = Rs. 5750

Therefore, Total amount paid in 10 installments is Rs. 45750 and Extra amount he has to pay is Rs. 5750.