Answer:
option B is correct, i.e. sum = 16.
Explanation:
Given the geometric series is: 20 -5 +5/4 -5/16 +....
First term, a = 20
Common ratio, r = -5/20 = -1/4
We know the formula for sum of infinite geometric series is given as follows:-
Sum = a/(1 - r)
Sum = 20/(1 - ((-1/4))
Sum = 20/(1 + 1/4)
Sum = 20/(5/4)
Sum = 20*4/5 = 16.
Hence, option B is correct, i.e. sum = 16.