Answer:
80 days
Explanation:
The equation ...
p(t) = 50(2)^(t/80)
tells you the value of p(t) will double when t increases by 80.
The population will double in 80 days.
_____
The order of operations requires that the equation in your problem statement be interpreted as ...
p(t) = 50(2^t)/80 = (5/8)2^t
This has a doubling time of 1 day, and starts with fractional rabbits.
Many curriculum materials suffer from poor editing of exponential equations. Any exponent that contains arithmetic operations must be enclosed in parentheses when it is written as plain text.