Question

Bernie counted the cars and motorcycles that passed his house in 45 minutes. He counted 29 vehicles and 82 tires. How many motorcycles passed his house?

Answer 1

Assuming that all cars have 4 tires and motorcycles have 2, we can write some equations relating what we know. Let C be the number of cars, and M be the number of motorcycles. There were 29 vehicles:
C+M=29

There were 82 tires, 4 per car and 2 per motorcycle:
4C+2M=82

Any questions about how I arrived at those equations?

Answer 2

No, I get how you got it. Thanks.