Problem Solving (PS) | Re: How many points (x y), where x and y are integers, lie inside of the t

HiBunuel GMATinsight ,

I chose to do the latter part of the question using Combinatorics.

To find the points that lie within the triangular region formed, weuse x+y<31

Now, this gives us 15 possible values ofx and 15 possible values of y (It is given that x & y are integers) i.e 30 values in total from which any 2 values can be picked (pls note: possible values include integers from 1-15 inclusive)

Using the formula, we get 30C2
Solving: 30!/28!x2!=435

Please let me know whether this way of solving is correct.

Thank you
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Statistics : Posted by Kriti1055 • on 05 May 2020, 03:57 • Replies 7 • Views 3350

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