The correct answer to this is 1.5. A geometric sequence is a set or sequence of numbers in which every term is mulptlied by a fixed, non-zero number or common ratio to get the succeeding term. The sequence described in the question is

where
a is the first term and b is the third term. The first term
a is multiplied by a common ratio
R to get 50, then 50 is multiplied again by
R to get the erd term
b, and
b is multiplied by thr common ratio
R to get 112.5, or in mathematical terms:
R × 50 ×
R = 112.5
