Solution:
6, 12, 18, 24 …. are the positive integers that are divisible by 6
This series creates an A.P., with the first term being 6 and the common difference being 6.
a = 6
d = 6
S40 = ?
Using the formula of sum of n terms, we know,
Sn = n/2 [2a +(n – 1)d]
As a result, putting the value of n as n = 40, we get,
S40 = 40/2 [2(6)+(40-1)6]
= 20[12+(39)(6)]
= 20(12+234)
= 20×246
= 4920