Let us assume the initial number of bacteria in the culture = x
After 1 hour,
The number of bacteria = 185x/100
= 1.85x
After 2 hours,
The number of bacteria = (185 * 1.85x)/100
= 3.42x
So
3.42x = 12500
x = 12500/3.42
= 3654.97
= 3655
From the above deduction, we can conclude that the initial number of bacteria in the culture is 3655