David W. answered • 07/11/15
Tutor
4.7
(90)
Experienced Prof
This question has TMI (too much information). Many questions will have TMI to confuse you.
The two rectangles have the same area. The problem gives the relationship of one rectangle to the other in percent and asks for the answer in percent, so we don't need to know the actual dimensions or even to see a picture!
Area = La* Wa = Lb * Wb
La = Lb * (0.9*Wa) / Wa [replace Wb with 0.9*Wa; divide both sides by Wa)
1 / 0.9 = Lb / La [divide both sides by La; cancel Wa]
1.1111 = Lb/La
Lb must be 1.1111 times as long as La. That is, Lb must be 11 1/9% longer than La (1.1111 times =11 1/9% longer).
Also, note that the possible answer, "10% longer," is included to catch students who don't realize that a percent of Rectangle B is different than a percent of Rectangle A.
David W.
Your comment puzzles me. The answer I gave is, " Lb must be 11 1/9% longer than La" and is the
same answer as Andrew gave: "The answer from the choices will be 11 1/9."
Also, the process is better -- there was no rounding and the unnecessary (TMI) calculations were excluded. Further, I included wise advice for approaching a problem and understanding distractors (wrong answers).
Thus, your statements are misguided. You may have any expert read and analyze these posts -- if they know what they are talking about, they will agree.
Best wishes anyway!!
Report
07/11/15
Jake P.
07/11/15