Question

If the number of tolls collected varies directly as the number of vehicles and $129 was collected from 20 vehicles, how many vehicles result in the collection of $3225? Show how you arrived at your answer

Answer 1

500 vehicles

Explanation:

let t represent number of tolls and v represent number of vehicles.

given that t varies directly with v then the equation relating them is

t = kv ← k is the constant of variation

to find k use the condition t = 129 from v = 20 , then

129 = 20k ( divide both sides by 20 )

6.45 = k

t = 6.45v ← equation of variation

when t = 3225 , then

3225 = 6.45v ( divide both sides by 6.45 )

500 = v

the number of vehicles is 500