The total cost, c ,of apples is proportional to the number of apples bought, a . The following table shows the relationship between the number of apples purchased and the cost. Which equation represents the relationship between the number of apples purchased and the cost?

A. c = 0.40a

B. c = 0.40a

C. c = 1.20a

D. c = 2.50a

c = 0.40a

Step-by-step explanation:

Total cost = c

Number of apples bought = a

Constant of proportionality = k = c/a

Equation of proportionality that will represent the situation will be in the form of:

c = ka

Let's find k:

k = c/a = 6.00/15 = 3.20/8 = 2.00/5 = 0.40

k = 0.40

To write the equation, substitute k = 0.40 into c = ka

Thus:

c = 0.40a