Copper pipe costs x cents per foot in 8-foot lengths, and x+y cents per foot in shorter lengths...

[BTGmoderatorLU]

Source: Princeton Review

Copper pipe costs x cents per foot in 8-foot lengths, and x+ y cents per foot in shorter lengths. What is the lowest possible price, in cents, of 51 feet of pipe in terms of x and y?

A. 51(x+y)
B. 51x
C. 48x+3y
D. 48(x+y)
E. 51x+3y

The OA is E

[Scott@TargetTestPrep]

Source: Princeton Review

Copper pipe costs x cents per foot in 8-foot lengths, and x+ y cents per foot in shorter lengths. What is the lowest possible price, in cents, of 51 feet of pipe in terms of x and y?

A. 51(x+y)
B. 51x
C. 48x+3y
D. 48(x+y)
E. 51x+3y

The OA is E

Solution:

For 51 feet of pipe, the cheapest option is to buy six 8-foot pipes and one 3-foot pipe. Therefore, the lowest possible price, in cents, of 51 feet of pipe, is:

6 * 8 * x + 1 * 3 * (x + y) = 48x + 3x + 3y = 51x + 3y

Answer: E

[swerve]

Source: Princeton Review

Copper pipe costs x cents per foot in 8-foot lengths, and x+ y cents per foot in shorter lengths. What is the lowest possible price, in cents, of 51 feet of pipe in terms of x and y?

A. 51(x+y)
B. 51x
C. 48x+3y
D. 48(x+y)
E. 51x+3y

The OA is E

Total required length \(= 51\)
So,
\(48x+3x+3y; 51x+3y\)