Find the minimum number of terms in the geometric series 10 + 8 + 32/5 + ... such that the sum is greater than 49.

Answer 1

In this GP, a = 10, r = 4/5

remember that
S(n) = a(1 - r^n)/(1-r)

Just like in your last question, find n so they are equal, then bump it up to the next whole number.