BRAINLIST +100 POINTS Last year, the numbers of skateboards produced per day at a certain factory were normally distributed with a mean of 20,300 skateboards and a standard deviation of 60 skateboards.

(a) On what percent of the days last year did the factory produce 20,420 skateboards or fewer?
(b) On what percent of the days last year did the factory produce 20,240 skateboards or fewer?
(c) On what percent of the days last year did the factory produce 20,480 skateboards or more?