A bicycle has two sets of gears, one at the pedals and one at the rear wheel. A typical 10-speed bicycle has two gears on the chain wheel and five gears on the rear wheel. The speed at which a bicycle travels depends on three independent factors:

- The first is the speed at which the cyclist pedals to turn the front gear (measured in rotations per minute).

- The second is the gear ratio from the front gear to the rear wheel (a ratio between the number of teeth on the rear gear).

- The third is the size of the rear wheel (measured as the diameter of the wheel).

a)Develop a formula that predicts the velocity in km/h for a bicyclist.

b)How fast will a cyclist travel (in km/h) who is pedalling at 50 rpm with a 42-toothed gear on the front, a 14-toothed gear on the back, and a tire with a diameter of 26 inches?

c)In what ways can a cyclist pedal more slowly but maintain the same speed?

I appreciate all the help I can get, I have no idea how to start solving this problem. Also, there doesn't seem to be anything about combining functions on purple math, unless I might have missed it.