Question

sam was building a suspension bridge for the playground at an elementary school and needed some chain link and rope.He bought a total of 80 feet of materials. The chain link cost $2.00 per foot, and the rope cost $1.50 per foot. He spent a total of $135. How much of each did he buy?

Answer 1

• 30 ft chain link
• 50 ft rope

Explanation:

Let c and r represent the quantities of chain link and rope that Sam purchases, respectively.

c + r = 80 . . . . . total of lengths purchased

2c +1.5r = 135 . . . . cost of amount purchased

Subtracting the second equation from twice the first gives ...

2(c +r) -(2c +1.5r) = 2(80) -(135)

0.5r = 25

r = 50

c = 30

Sam bought 30 feet of chain link and 50 feet of rope.