S = a0 / (1 - r)
S is the sum
a0 is the first term
r is the ration
The sum is 2, and the first term is 0.5, so plug in what you know and see what you come up with:
2 = 0.5 / (1 - r)
That's an equation you can solve:
2(1 - r) = 0.5
1 - r = 0.5 / 2 = 0.25
0.75 - r = 0
0.75 = r
Ratio is 0.75.
