Question

Ms. Lewis is hiring a carpenter to repair her shed. The cost of Carpenter L is shown in the table.

A table titled Carpenter L Costs is shown. It has three columns and two rows. Row one is labeled Hours, h. Row two is labeled Cost, c. One hour, one hundred eighty-seven dollars. Two hours, two hundred fifty-nine dollars. Three hours, three hundred thirty-one dollars.

Part A. What is the initial cost and hourly rate of Carpenter L?

Part B. Write an equation to represent the function shown in the table.

Part C. Carpenter N charges $60 per hour and an additional $195 for the materials needed. What is the difference in cost between Carpenter N and Carpenter L if the repair takes 6 hours?

Enter the correct answers in the boxes.

Answer 1

A. $115; $72/hour

B. c = 72h + 115

C. $8

Explanation:

Part A.

1 hour: $187

2 hours: $259

2 hours - 1 hour = 1 hour

$259 - $187 = $72

$72/hour

The hourly rate is $72/hour.

Since for the first hour he charges $187, and only $72 comes from the hourly rate, then the initial cost is $187 - $72 = $115.

The initial cost is $115.

Part B.

c = 72h + 115

Part C.

Carpenter L for 6 hours:

c = 72(6) + 115 = 547

$547

Carpenter N for 6 hours:

60(6) + 195 = 555

$555

Difference: $555 - $547 = $8