Question 415817
The initial population is Po.  This problem describes the equation for the growth of a poplulation as a function of time.
I assume the initial population is 10,000?
Then the equation reads {{{P(t)=1500*sqrt(t) + 10000}}}.  
I assume the problem is asking for the time, t, at which the population reaches a particular value, P?  If so, then we need to solve for t:
{{{(P(t)-10000)/1500 = sqrt(t)}}}.  Inserting the value given for P and squaring both sides gives us the answer.