A bicyclist races on a bicyclist with 13-inch-radius wheels. When she is traveling at a speed of 37 ft/sec, how many revolutions per minute are her wheels making?

Radius of a wheel = 13 inch

= 1.08333 ft

circumference of a wheel = 2*pi*r^2

= 2 * (22/7) * 1.08333^2 ft

= 2 * (22/7) * 1.1736 ft

= (44/7) * 1.1736 ft

= 51.6384/7 ft

= 7.3769142857 ft

distance covered in one minute = 37 * 60 ft/min

= 2220 ft/min

now, revolution per minute = 2220 / 7.3769142857

= 300.93884

therefore her wheels are making 300.93884 revolutions per minute