The probability that I dial a wrong number when making a telephone call is 0.015. In a typical week I will make 50 telephone calls. Using a Poisson approximation to a binomial model find, correct to two decimal places, the probability that in such a week,

(a) I dial no wrong numbers,

(b) I dial more than two wrong numbers. Comment on the suitability of the binomial model and of the Poisson approximation.