Q11 of 47 Page 1

Find the sum of first 15 multiples of 8.

First 15 multiples of 8 are 8, 16, 24, 32,…………..

This, clearly is an AP


where,


a = 8


And,


d = 16 – 8 = 8


We know that,


Sum of first n terms of an AP,







⇒ S15 = 15 × 64


⇒ S15 = 960


Hence, sum of first 15 multiples of 8 = 960


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