How many different words can be made from the word REVIEW, such that W is always before R?
(Sorry I don't have options)
Permutations-word arrangement
This topic has expert replies
-
- Junior | Next Rank: 30 Posts
- Posts: 26
- Joined: Fri Feb 26, 2010 8:56 pm
- Thanked: 2 times
a total of 6!=6*5*4*3*2*1=720 different words can be made from these six letters
the possibilty that W is before R and R is before W is the same
thus we have 720*50%=360
the possibilty that W is before R and R is before W is the same
thus we have 720*50%=360
it is not an "alice in wonderland". it is real! i am going to freak GMAT out!
-
- Senior | Next Rank: 100 Posts
- Posts: 60
- Joined: Wed Jan 07, 2009 1:56 pm
- Thanked: 12 times
- GMAT Score:750
Good call that we can simply divide the total by two since the number with R before W and vice versa would be the same. However, we also need to account for the fact that the word has two Es. Therefore, you need to take 6!/2! in the overall total. Final answer should be 180.seanceserene wrote:a total of 6!=6*5*4*3*2*1=720 different words can be made from these six letters
the possibilty that W is before R and R is before W is the same
thus we have 720*50%=360
Note: E.g. If you take 6! instead of 6!/2! you are counting EERVIW twice
-
- Junior | Next Rank: 30 Posts
- Posts: 26
- Joined: Fri Feb 26, 2010 8:56 pm
- Thanked: 2 times
Great! thank you for pointing out my mistake!!arzanr wrote:Good call that we can simply divide the total by two since the number with R before W and vice versa would be the same. However, we also need to account for the fact that the word has two Es. Therefore, you need to take 6!/2! in the overall total. Final answer should be 180.seanceserene wrote:a total of 6!=6*5*4*3*2*1=720 different words can be made from these six letters
the possibilty that W is before R and R is before W is the same
thus we have 720*50%=360
Note: E.g. If you take 6! instead of 6!/2! you are counting EERVIW twice
carelessness is my greatest enemy in Math
hope that i don't make the same mistake next time
it is not an "alice in wonderland". it is real! i am going to freak GMAT out!
- outreach
- Legendary Member
- Posts: 748
- Joined: Sun Jan 31, 2010 7:54 am
- Thanked: 46 times
- Followed by:3 members
the word REVIEW can be grouped in 6! ways=6*5*4*3*2*1= 720
since two E present in the word, divide eq 720 by 2!=> 360
since W is always before R divide 360 by 2!=180
since two E present in the word, divide eq 720 by 2!=> 360
since W is always before R divide 360 by 2!=180
-------------------------------------
--------------------------------------
General blog
https://amarnaik.wordpress.com
MBA blog
https://amarrnaik.blocked/
--------------------------------------
General blog
https://amarnaik.wordpress.com
MBA blog
https://amarrnaik.blocked/