Velocity rider

Question

What formulas to I use to work this out. Thanks for your help. 

 

A person is riding a bike with a tail wind of 12 m/s. The velocity of the cyclist is 55km/h. What is the velocity of the rider relative to the wind? 

Answer 1

55-12 = 43 m/s is the speed of the cyclist without the wind

 

The cyclist is

43/12 = 3 and 7/12 times as fast as the wind