Question

Bill mixes candy costing 45cents per pound with candy costing 65cents a pound. A 7-pound box of the mix costs $3.65. How much of each kind of candy should Bill use?

Answer 1

Bill should use 4.5 pounds of the candy costing 45 cents and 2.5 pounds of the candy costing 65 cents.

Explanation:

With the information provided, you can say that the sum of the pounds of each type of candy is equal to 7, which can be expressed as:

x+y=7

Also, the statement indicates the 7 pound box costs $3.65 and you can say that the sum of the results of multiplying the price of each candy for the number of pounds is equal to $3.65, which is:

0.45x+0.65y=3.65

You have the following equations:

x+y=7 (1)

0.45x+0.65y=3.65 (2)

Now, you have to solve for x in (1):

x=7-y (3)

Then, you have to replace (3) in (2):

0.45(7-y)+0.65y=3.65

3.15-0.45y+0.65y=3.65

0.20y=0.50

y=0.50/0.20

y=2.5

Finally, you can replace the value of y in (3) to find x:

x=7-y

x=7-2.5

x=4.5

According to this, the answer is that Bill should use 4.5 pounds of the candy costing 45 cents and 2.5 pounds of the candy costing 65 cents.