A man starts repaying a loan as first instalment of Rs. 100. If he increases the instalment by Rs 5 every month, what amount he will pay in the 30th instalment?

First instalment = Rs 100


Instalment increases by Rs 5


Second Instalment = Rs 105


So, every month instalment Increases by 5


Man repays 100, 105, 110, ………… every month


This forms an A.P.


A.P. is 100, 105, 110, 105, …….


First term of A.P. = 100


Common difference = 5


nth term of A.P. = tn = a + (n – 1)d


30th term = t30 = 100 + (30 – 1) × 5


= 100 + 29 × 5 = 100 + 145


t30 = 245


Man will pay Rs 245 in 30th instalment.


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