Peter has a summer job mowing lawns. He charges a weekly rate of $3 for gas and then $20 per hour per family. Last week, Peter earned $53 mowing the Smith's lawn. How many hours did Peter spend mowing the lawn?

In the film, zeke the zombie slayer versus the zombies from space, zeke slayed 140 zombies. in the sequel, zeke the zombie slayer versus the zombies from space, part 2, he slayed 5% more zombies. how many zombies were slain by zeke in the sequel?

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?