Richard and Tom each mow lawns in the summer to earn money. The lawns they mow are all approximately the same size. Richard’s earnings are shown in the graph and Tom’s earnings are shown in the table.
Tom’s Earnings

Number of Lawns Earnings
3 $22.50
8 $60
12 $90
15 $112.50

How much money, in dollars, does each person earn per lawn mowed?

Richard earns $___per lawn.

Tom earns $___per lawn.