Question

Find the sum of first 40 positive integers divisible by 6.
​

Answer 1

your answer is 4920

hope it helps you

Answer 2

first 40 positive integers divisible by 6 are :

6,12,18,24....

a=6,d=6 ,n=40

Sn=n/2{2a+(n-1)×d}

=40/2 {2×6+(40-1)×6}

=20 {2×6+39×6}

=20 (2×6+234)

=20×246

=4920

hope it helps u...!!!