Mary counted 12 cyclists and 31 bicycle wheels at a zebra crossing. How many are bicycles and how many are tricycles?

Question

Quadratic and Simultaneous Equations.

Answer 1

Let B=no. of bicycles and T=no. of tricycles. The number of wheels=31=2B+3T and the number of cyclists=12=B+T, so T=12-B. Therefore 2B+3(12-B)=31; 2B+36-3B=31 and B=5. So T=12-5=7.

There are 5 bicycles and 7 tricycles.