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?

6

10

12

17

Answer 1

Let m= motorcycles
Let = cars

m+c= 29 vehicles
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a car has 4 wheels, and a motorcyle has 2 wheels.

so 4c + 2m = 82 tires
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Answer 2

so we have m+c = 29 vehicles
c= 29-m

Replace this value of c in the 2nd equation.

4(29-m) +2m= 82
116 -4m+2m= 82
34 = 2m
m= 17

so there were 17 motorcycles.