Leo has the pizza business. The times to make and deliver pizzas are approximately normally distributed with the mean m =20 minutes and standard deviation s = 10 minutes.
1. Assume that Leo advertises " If it takes more than 30 minutes to get your pizza, you get it free". What percentage of his take-out pizzas will have to offer away free? SW
2. How long a time must Leo allow if he wants to give away no more than 5% of pizzas?