Probability (interesting)

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Probability (interesting)

by aj5105 » Tue May 26, 2009 1:40 am
In x-y quadrant, there is a square with vertices (0,0) , (0,4) , (4,0) and (4,4) . What is the probability that the point on the square wil satisfy the condition x + 2y >= 3 .

Solution:

x + 2y > 3

x + 2y = 3

To get a line that cuts the square we need to substitute values for x and get y correspondingly.

Put x = 0, y = 3/2
x = 1, y = 1
x = 2, y = 1/2
x = 3, y = 0

We want region x + 2y > 3
That is 1/2 * 3/2 * 3 (Considering maximum value of x & y)

Now the probability.

(16 - 9/4)/16 = 53/64

Am I right here?
Source: — Problem Solving |

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by bluementor » Tue May 26, 2009 2:31 am
You are right all the way up to your final answer, which is computed wrongly. You should arrive at 55/64.

-BM-

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by aj5105 » Tue May 26, 2009 2:45 am
Thanks BM for validating.

~AJ~

bluementor wrote:You are right all the way up to your final answer, which is computed wrongly. You should arrive at 55/64.

-BM-

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by Svedankae » Tue May 26, 2009 5:30 am
is this a gmat-like question?

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by Brent@GMATPrepNow » Tue May 26, 2009 9:38 am
Svedankae wrote:is this a gmat-like question?
Good question, Svendankae.
On ocassion, an out-of-scope question appears in this forum. This question, however, is a GMAT-like question. In fact, this might even be a retired official question. If it isn't, I have seen an official question similar to this one.
Brent Hanneson - Creator of GMATPrepNow.com
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