Question

For a G.P., if a= 2,r=3 , Sn = 242then n is____​

Answer 1

Answer:

n = 5

Step-by-step explanation:

Using, the formula for Sn of G.P.

Sn = a(rⁿ-1)/(r-1) = 2×(3ⁿ-1)/(3-1) = 3ⁿ-1

=>3ⁿ-1 = 242

=> 3ⁿ = 243 = 3⁵

=> n = 5

Answer 2

for a G.P.,if a = 2,r=3, sn= 242then n is 18