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06 Feb 2016, 06:46
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Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
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Please guide me to how to get the answer for the below question..
How many words of 3 letters can be formed from the letters "AABBCC"?
In this case we have 3 differents letters that repeat each others 2 times
For a word of 3 differents letters we have :
3C3 x 3! or 3P3
But for 2 same letters and one different i get stuck ..
is it 3C1 * 2C2 * 3!/2! ?
thanks in advance!!!
How many words of 3 letters can be formed from the letters "AABBCC"?
In this case we have 3 differents letters that repeat each others 2 times
For a word of 3 differents letters we have :
3C3 x 3! or 3P3
But for 2 same letters and one different i get stuck ..
is it 3C1 * 2C2 * 3!/2! ?
thanks in advance!!!
06 Feb 2016, 07:12
Kudos
Bookmarks
souley
Hi,
it is not tyeh correct way to post a Q.
pl go through the links ..
However to answer your query..
Quote:
1) first choose 2 out of three letters= 3C2..
2) these two have two ways to be placed.. two times and one times= 2!
3) ways to arrange three letters, of which 2 are same= 3!/2!..
total ways for your query= 3C2*2!*3!/2!=18
all same you have already found= 3!=6..
add two and you get your answer
Hope it helps..
06 Feb 2016, 07:21
Kudos
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There are 4 different ways to form the word:
- 3 different letters (ex.: ABC): 3*2*1 = 6 options
- The first letter is equal the second but is different from the third (ex.: AAB): 2*3C2 = 6 options
- The first is different and the second and third are equal (ex.: ABB): 2*3C2 = 6 options
- The first letter is equal the third and the second is different (ex.: ABA): 2*3C2 = 6 options
So we have 4*6 = 24 options.
Hope this helps.
- 3 different letters (ex.: ABC): 3*2*1 = 6 options
- The first letter is equal the second but is different from the third (ex.: AAB): 2*3C2 = 6 options
- The first is different and the second and third are equal (ex.: ABB): 2*3C2 = 6 options
- The first letter is equal the third and the second is different (ex.: ABA): 2*3C2 = 6 options
So we have 4*6 = 24 options.
Hope this helps.
