Question

The cost for renting a weed trimmer varies directly with the number of hours used. A weed trimmer rented for 5 hours costs $32.50.Which choice shows the direct variation equation and the amount of rent for 8 hours in this situation?
A y = $6.5x, y = $52.00
B y = $32.5x, y = $260.00
C y = $5x, y = $40.00
D y = $8x, y = $64.00

Answer 1

let the cost for renting be y and the number of hours be x
then:
y=kx
where:
k is the constant of proportionality
k=y/x
y=$32.5 when x=5 hours
thus;
k=32.5/5
k=6.5
hence the equation is:
y=6.5x
thus the value of y when x=8 hours will be:
y=6.5(8)=$52
Answer:'

A y = $6.5x, y = $52.00