Solving this problem requires the supplement of the actual
expression. However I believe you forgot to include it with the question.
However I believe that the expression is in the form of:
y = A e^(-k t)
where,
y is the number of bacteria after time t
A is a constant and represents the initial number of bacteria
k is the growth rate in decimal form
t is time
So whatever is located in A is the initial number of bacteria,
while k times 100% is the growth rate.
