83 Area of parallelogram

Expert replies

ern5231: Master | Next Rank: 500 Posts; Posts: 226; Joined: Sun Aug 09, 2009 4:34 am

by ern5231 » Sun Oct 04, 2009 8:35 am

A parallelogram has one side length=6 and another side length=7. What could be the possible area?
I 21
II 42
III 81

The OA speaks of having 21 as the valid answer. How is that possible?

Like this post

Source: Beat The GMAT — Problem Solving | Sun Oct 04, 2009 8:35 am

ashis979: Junior | Next Rank: 30 Posts; Posts: 26; Joined: Tue Jul 28, 2009 8:12 pm; Thanked: 4 times

by ashis979 » Sun Oct 04, 2009 11:00 am

21 it is.

I: Parallelogram with base 7
Since the base is 7, the other side is 6. 6 also the hypotensue of the right triangle that you will draw in order to determine the height of the parallelogram. However, no calcs necessary. Since 6 is the hypotenuse, the height has to be less than 6 and the area of the parallelogram would be 7*less than 6 = less than 42...go with I

II. Parallelogram with base 6
Same as above. In this case the hypotenuse is 7 and therefore the base must be less than 7. So area of the parallelogram would be 6*less than 7 = less than 42...again, go with I

Like this post

sanjana: Master | Next Rank: 500 Posts; Posts: 182; Joined: Sun Aug 02, 2009 7:19 pm; Thanked: 18 times; GMAT Score:680

by sanjana » Mon Oct 05, 2009 10:38 am

I agree with 21,But couldnt the answer also be 42
If we make the 2 sides perpendicular to eachother,it becomes a rectangle which is also a parallelogram and the area will be 6*7.

Are we not considering this case because the question mentions Parallelogram?
I'm confused! :roll:

Like this post

ashis979: Junior | Next Rank: 30 Posts; Posts: 26; Joined: Tue Jul 28, 2009 8:12 pm; Thanked: 4 times

by ashis979 » Mon Oct 05, 2009 11:32 am

I avoided considering a rectangle assuming that the question would have made that distinction. Not to mention 42 seemed like too obvious a choice. But you are correct to assess that it could very well be just 6*7=42 or the other way around. I have certainly seen questions like "Is ABCD a parallelogram?" where you need to consider all possibilities, rect, sq, rhom.

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review