the average number of passengers on a subway car is 60. If the number of passengers on a car has normal distribution with a standard deviation of 20, approximately what the percent of subway cars carry more than 80 passengers?

Answer 1

your data is perfectly suited for this webpage, which replaces the tables you probably have at the back of your text
I got 15.87%

http://davidmlane.com/hyperstat/z_table.html