Question

assume that a tree is randomly distributed in a degraded forest preserve with lambda=40 trees/seedlings per 100 m2 (meter squared). if two 100 m2 (meter squared) plots are randomly chosen then what is the probability that one of the plots has at least 30 trees/seedlings while the other plot has 30 or less such trees? (no continuity correction, hint: use a normal approximation to a poisson).