A local natural history museum charges admission to groups according to the following policy. Groups of fewer than 50 people are charged a rate of $3.50 per person, while groups of 50 people or more are charged a reduced rate of $3 per person.

a. Express the amount a group will be charged for admission as a function of its size and draw the graph.

b. How much money will a group of 49 people save in admission costs if it can recruit 1 additional member?