ENTRANCE

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ENTRANCE

by GmatKiss » Mon May 21, 2012 5:30 am
Find the number of selections that can be made taking 4 letters from the word"ENTRANCE".
(A) 70
(B) 36
(C) 35
(D) 72
(E) 32
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by Anurag@Gurome » Mon May 21, 2012 7:02 pm
GmatKiss wrote:Find the number of selections that can be made taking 4 letters from the word"ENTRANCE".
(A) 70
(B) 36
(C) 35
(D) 72
(E) 32
(1) All letters are different, means that we have to choose 4 letters form 6 different letters, this can be done in 6C4 = 15
(2) 2 N's and other letters are different, so 2C2 (2 N's out of 2) * 5C2 (other 2 letters from different 5 letters left) = 10
(3) 2 E's and other letters are different, so 2C2 (2 E's out of 2) * 5C2 (other 2 letters from different 5 letters left) = 10
(4) 2 N's, 2 E's, so 2C2 * 2C2 = 1.

Total number of selections = 15 + 10 + 10 + 1 = 36

The correct answer is B.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
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