A plumber charges a flat fee of $73 to visit a home and examine a clogged drain. The plumber charges an additional $25 per hour spent fixing the drain. The total cost, C (in dollars), for fixing a drain that takes h hours is given by the following. C=25h+73 (a) What is the total cost for fixing a drain that takes 5 hours? (b) If the plumber charged a total of $398, how many hours did he spend fixing the drain?