Answer:
10
Step-by-step explanation:
The formula for calculating the sum to infinity of a GP is expressed as;

a is the first term
r is the common ratio
From the given sequence;
First-term a = 5
Common ratio r = 2.5/5 = 1.25/5 = 0.5
Substitute the given values into the formula

Hence the sum to infinity of the series is 10