BTGModeratorVI wrote: ↑Mon Sep 07, 2020 7:02 am
A rope 40 feet long is cut into two pieces. If one piece is 18 feet longer than the other, what is the length, in feet, of the shorter piece?
(A) 9
(B) 11
(C) 18
(D) 22
(E) 29
Answer:
B
Source: Official guide
APPROACH #1: Algebra
Let x = the length of the shorter piece
So, x + 18 = the length of the longer piece
Since the lengths of the two pieces must add to 40 feet, we can write: x + (x + 18) = 40
Simplify: 2x + 18 = 40
Subtract 18 from both sides: : 2x = 22
Solve: x = 11
Answer: B
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APPROACH #2: Test the answer choices
Start with the middle answer choice C
C) 18
If the shorter piece is 18 feet long, then the longer piece is 36 feet long
Sum of lengths = 18 + 36 = 54
NO GOOD. We want a sum of 40 feet (as per the question)
So, we can ELIMINATE C.
Also, since we need the two pieces to be SHORTER, we can also ELIMINATE D and E
Now try answer choice B
B) 11
If the shorter piece is 11 feet long, then the longer piece is 29 feet long
Sum of lengths = 11 + 29 = 40
PERFECT!!!
Answer: B
Cheers,
Brent
