Question

find the sum of first positive integers divisible by 3

Answer 1

I hope it will help you

Answer 2

step 1 Address the formula, input parameters & values.

Input parameters & values:

The number series 3, 6, 9, 12, 15, 18, 21, . . . . , 120.

The first term a = 3

The common difference d = 3

Total number of terms n = 40

step 2 apply the input parameter values in the AP formula

Sum = n/2 x (a + Tn)

= 40/2 x (3 + 120)

= (40 x 123)/ 2

= 4920/2

3 + 6 + 9 + 12 + 15 + 18 + 21 + . . . . + 120 = 2460

Therefore, 2460 is the sum of first 40 positive integers which are divisible by 3.