Question

Four pounds of apples cost $5. Eight pounds of apples cost $10. If the total cost of apples, y, varies directly with the number of pounds of apples purchased, x, what is the cost of 6 pounds of apples? Round your answer to the nearest hundredth. $0.80 $1.25 $4.80 $7.80

Answer 1

The cost of 6 pounds of apples would be $ 7.50

Explanation:

4 pounds of Apple cost = $ 5

8 pounds of Apple cost = $ 10

Cost of apples(y) varies directly with the number of pounds of apples(x), so we can express this as:

`y \propto x`

Introducing the constant of proportionality, we get:

`y=kx`

Using, y = 5 and x =4, we get:

`5=4k\\\\ k = 1.25`

Thus, the relation between y and x will be:

y = 1.25x

So, for 6 pounds of apples, we have x = 6. Using this value in above equation, we get:

y = 1.25 x 6

y = $ 7.50

Thus, the cost of 6 pounds of apples would be $ 7.50