Question

find the sum of 1+5+5^2+.....upto 8 terms

Answer 1

1(5^8-1)/5-1 = 97656

Answer 2

Answer:  97656

Step-by-step explanation:

The given geometric progression $=1+5+5^2+.......................$

Here a=1 and r=5

We know that the sum of geometric progression is given by:-

$S_n=\frac{a(r^n-1)}{(r-1)}$

To find the sum upto 8 terms, substitute n=8 in the above formula, we get

$S_8=\frac{1(5^8-1)}{(5-1)}=\frac{390625-1}{4}=\frac{390624}{4}=97656$

Hence, the sum of the given g.p. is 97656