BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Probabilit

Expert replies
Source: — Problem Solving |

by Patrick_GMATFix » Sat Dec 21, 2013 8:57 pm
The two solutions below are taken from the GMATFix App.

Solution A
Image

Solution B
Image

-Patrick
  • Ask me about tutoring.
Join the discussion

by Stuart@KaplanGMAT » Sun Dec 22, 2013 1:37 am
Hi!

This may look like a probability question, but it's really all about geometry. The question is really asking "what portion of ABCD is shaded?"

This question is super quick if you use your graph-lined noteboard to draw the shape to scale - you'll quickly see that the mini square in the bottom right is 1/16 of the entire shape and that the shaded region is identical to 3 of that mini square, so it comprises 3/16 of the big square.

No more work required, 3/16 is the correct answer.

What are the big takeaways from this question?

1) Redraw shapes on your noteboard, especially when they're not to scale.

2) The more complicated the question, the more time you need to spend deconstructing it. If you start doing calculations without understanding what the question is asking, you're just wasting time!

Stuart
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Join the discussion

by GMATGuruNY » Sun Dec 22, 2013 4:32 am
[email protected] wrote:Request you to explain in detail the concept!
As Stuart has wisely suggested, REDRAW the figure on your grid-covered noteboard so that AE=ED:

Image

ABCD is composed of 16 little squares.
Of these 16 squares, 3 make up the shaded region.
P(x will be in the shaded region) = 3/16.

The correct answer is D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Join the discussion