please answer this operations management question, thank you.

A newspaper boy is trying to perfect his business in order to maximize the money he can save

for a new car. Daily paper sales are normally distributed, with a mean of $100$ and standard

deviation of $10.$ He sells papers for $$0\mathrm{.}50$ and pays $$0\mathrm{.}30$ for them. Unsold papers are trashed

with no salvage value. How many papers should he order each day and what $\%$ of the time will

he experience a stockout? $(9$ Points$)$