Find the sum of 3 + 32 + 33 + ............+ 38
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 9840.
Given that
The sum of 3 + 32 + 33 + ............+ 38
First term a = 3
The common ratio r = 32/3 = 3
Term = 8
The sum of a G.P. series of n terms Sn = a(rn - 1)/(r - 1)
⇒ Sn = 3 (38 - 1)/(3 - 1)
⇒ Sn = 3 × 6560/2 = 9840