Question

The mean number of errors due to a bug occurring in a minute is 0.0001. What is the probability that no error will occur in 20 minutes?

Answer 1

$\lambda =0.0001\; per\; a\; minute\\ \lambda =20\times 0.0001=0.002\; per\; 20\; minute\\ P(X=0)=\frac{e^{-0.002}(0.002)^{0}}{0!}\approx0.998$