Question

There are 14 bicycles and tricycles in a bicycle shop. Each bicycle has 2 wheels and each tricycle has 3 wheels. There are 37 wheels in all. How many bicycles are there?

Answer 1

2b + 3(14-b) = 37

Answer 2

B = # of bicycles
T = # of tricycles

2B+3T=37
B+T=14

If we make T=14-B, then we can substitute that into the first equation to find B:

2B+3(14-B)=37
2B+42-3B=37
-B+42=37
-B=-5
B=5

So there are 5 bicycles (along with 9 tricycles).