(Q32).Find the sum of the first 40 positive integers divisible by 6.

The given numbers are the first 40 positive multiples of 6

⇒ 6 × 1, 6 × 2, 6 × 3, ….., 6 × 40

⇒ 6, 12, 18, ….. 240

Sn =
n
2
 (a+l)
S40 =
2
 ( + )

= ×

=

∴ S40 =