Find the sum of the first 15 multiples of 8.

By Shivank Goel|Updated : August 5th, 2022

The Sum of the first n terms of an AP is written as

Sₙ = n/2 [2a + (n - 1) d]

Or Sₙ = n/2 [a + l]

Where a is the first term,

d is the common difference

n is the number of terms

8, 16, 24, 32, ..... are the multiples of 8 which are in AP

a = 8

d = 8

n = 15

By substituting these values in the formula

S₁₅ = 15/2 [2 x 8 + (15 - 1)8]

= 15/2 [16 + 14 x 8]

= 15/2 [16 + 112]

So we get

= 15/2 x 128

= 15 x 64

= 960

Therefore, the sum of the first 15 multiples of 8 is 960.

Summary:

Find the sum of the first 15 multiples of 8.

The sum of the first 15 multiples of 8 are 960.

Comments

write a comment

PO, Clerk, SO, Insurance

BankingIBPS POIBPS ClerkSBI POIBPS SOSBI ClerkRBIIDBI SORRBLICESICNainital BankOtherQuick LinkMock Test

Follow us for latest updates