Find the sum of first fifteen multiples of 8.

Question

KnowledgeBoat · Accepted Answer

8, 16, 24,......,(upto 15th term). The above is an A.P. with common difference equal to 8. We know that, Sum of n terms of an A.P. is given by, ∴ Sn = [2a + (n - 1)d] Given, a = 8 d = 16 - 8 = 8 n = 15 S15 = [2(8) + (15 - 1)8] = [16 + (14)8] = [16 + 112] = (128) = 15 × 64 = 960. Hence, S15 = 960.

Mathematics

Find the sum of first fifteen multiples of 8.

AP

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