Help! Poisson distribution

The number of sales made by a telemarketer follows a Poisson distribution with a rate of 5.6 per shift.

a) The telemarketer sets a goal of making at least four sales during her shift. What is the probability that she achieves her goal?

b) What is the probability that the telemarketer makes 25 sales in a five-day work week (assuming she works one shift per day)?