Estimate the number of chocolate chips a cookie will have on average

Question

Given that 1 in 200 cookies have no chocolate chips, estimate the number of chocolate chips a cookie will have on average.

I'm not sure where to even begin for this question. Any suggestions?

Answer 1

Clue: Suppose the number of chocolate chips in a cookie has a Poisson distribution. If $X \sim \mathsf{Pois}(\lambda),$ then $P(X = 0)$ tells you $\lambda.$