Gerda discovers that the lifetime of light bulbs is normally distributed with mean 1000 hours and standard deviation 100 hours. If Gerda buys 50 bulbs, how many of them are expected to last less than 800 hours? Give your answer correct to the nearest integer.

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?