If I charged 30$ a hair cut the whole year how many times would each customer have to come in to get 17,510$

The number of nails of a given length is normally distributed with a mean length of 5.00 in, and a standard deviation of 0.03 in. find the number of nails in a bag of 120 that are less than 4.94 in. long.

How do i do this activity, is appreciated

Can anyone me with 32,33,36,37,and 40.