#### Question

Find the sum of first 8 multiples of 3

#### Solution 1

First, 8 multiples of 3 are { 3, 6, 9...,24}

We can observe they are in AP with first term (*a*) = 3 and last term (*l*) = 24 and number of terms are 8.

`S_n = n/2 (a + l)`

`=> S_n = 8/2(3 + 24)`

`S_8 = 4 xx (3 + 24) = 108`

Hence, the sum of the first 8 multiples of 3 is 108

#### Solution 2

First 8 multiples of 3 are

3, 6, 9, 12, 15, 18, 21, 24

The above sequence is an A.P

a= 3, d= 3 and last term l = 24

`S_n = n/2 (a + 1) = 8/2[3 + 24] = 4(27)`

`S_n = 108`

Is there an error in this question or solution?

Solution Find the Sum of First 8 Multiples of 3 Concept: Sum of First n Terms of an AP.