To find the number of rabbits present after 15 years using the given function \( P(t) = 500e^{0.5t} \), we need to substitute \( t = 15 \) into the function.
\[ P(15) = 500e^{0.5 \times 15} \]
Calculating \( 0.5 \times 15 \):
\[ 0.5 \times 15 = 7.5 \]
Now substituting back into the function:
\[ P(15) = 500e^{7.5} \]
Next, we need to calculate \( e^{7.5} \). Using a calculator, we find:
\[ e^{7.5} \approx 1808.042 \]
Now we calculate \( P(15) \):
\[ P(15) = 500 \times 1808.042 \approx 904021 \]
Rounding to the nearest rabbit, the number of rabbits present after 15 years will be:
\[ \text{There will be } 904021 \text{ rabbits.} \]