One possible gear ratio on Matthew's mountain bike is 4 to 1. This means that the front gear has four times as many teeth as the gear on the back wheel. So each revolution of the pedal causes the rear wheel to make four revolutions.
a. If Matthew is pedaling 60 revolutions per minute (r/min), how many revolutions per minute is the rear tire making?
b. If the diameter of the rear tire is 26 in., what speed in miles per hour will Matthew attain?
c. Matt downshifts to a front gear that has 22 teeth and a rear gear that has 30 teeth. If he keeps pedaling 60 r/min, what will his new speed be?