Jaspal Singh repays his total loan of Rs118000 by paying every month starting with the first installment of Rs1000. If he increases the installment by Rs100 every month, what amount will be paid by him in the 30th installment? what amount of loan does he still have to pay after the 30th installment?

Given that,


Jaspal singh takes total loan = Rs118000


He repays his total loan by paying every month.


His first installment = 1000


Second installment = 1000 + 100 = 1100


Third installment = 1100 + 100 = 1200 and so on


Thus, we have 1000, 1100, 1200, … which form an AP, with


first term, a = 1000


common difference, d = 1100 – 1000 = 100


nth term of an AP


So amount paid in 30 installments = sum of first 30 terms of this AP




= 15(2000 + 2900)


= 15(4900) = 73500


So he pays Rs 73500 in 30 installments


Loan left = total loan - paid lone


= 118000 - 73500 = 44500 Rs


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