I have two questions that are based on the following chart:

Activity Cal/h
Bicycling 6mi/h 240
Bicycling 12 mi/h 410
Cross country sking 700
Jogging 5 1/2 mi/h 740
Jumping rope 650
Running 10 mi/h 1,280
Swimming 25 yd/min 275
Swimming 50 yd/min 500
Tennis (singles) 400
Walking 2 mi/h 240
walking 3mi/h 320
walking 4 1/2 mi/h 440

1. At what rate would a 120lb person burn calories while bicycling at 12 mi/h?
2.At what rate would a 180lb person burn calories while bicycling at 12 mi/h?
I just don't understand how to set up the problems so I can find the answer. I don't want the answer just how to set up the problems so that I can figure out the answer for myself. Thanks for helping!