Organic apples are on special for $1.30 per pound. Does total cost vary inversely or directly with the number of pounds purchased? Find the cost of
4.2 pounds of apples,
A. Directly: $3.23
B. Directly: $5.46
C. Inversely: $3.23
D. Inversely: $5.46

B. Directly: $5.46

Step-by-step explanation:

If two variable x and y varies directly, it means that amount of   change of value of x causes proportional change in value of y  (that is if there is increase in x there is increase in y. if there is decrease in x there is decrease in y)

If two variable x and y varies inversely, it means that if value of x increases by some amount then  value of y decreases in same proportion and vice versa.

cost of one pound of Apples = $1.30

Thus, if one buys two pound of Apples he has to pay twice of cost of one pound of Apples(i.e 2*$1.30)

if one buys three pound of Apples he has to pay thrice of cost of one pound of Apples(i.e 3*$1.30)

Thus, we see that as number of pounds of apple increases the cost also increases in same proportion.

So , bases on above definition of direct and inverse relation it can be said that  total cost vary  directly with the number of pounds purchased.

We have to find cost of 4.2 pounds of apple

hence,

cost of 4.2 pounds of apple = cost of one pound of Apples * 4.2

                                               = $1.30 * 4.2 = $5.46 (Answer)

Thus answer from above choice is B. Directly: $5.46