Krishna P.

asked • 11/24/14

In how many ways we can arrange the word TEACHER such that no two vowels should be together.

In how many ways we can arrange the word TEACHER such that no two vowels should be together.

Krishna P.

Kindly give full explanation .
Report

11/24/14

2 Answers By Expert Tutors

By:

Ben B.

Tom,
 
Good catch on the CCC and CC..CC combinations - I missed those. Wouldn't there be 3 combinations for each vowel arragement, where the A could be first, in the middle, or last, e. g.
A..E..E
E..A..E
E..E..A
 
If so that would make 8*4!*3 total.
 
- Ben
Report

11/25/14

Tom F.

tutor
Hi Ben,
 
Thanks you are right.  Not sure why I had 2 instead of 3.  I will correct the answer.
 
Tom
Report

11/25/14

Ben B. answered • 11/24/14

Tutor
5 (8)

Experience Aerospace Engineer with Master's Degree in Physics

Krishna P.

Sir, Kindly give full explanation .
Report

11/24/14

Ben B.

There are 4 consonants, and 3 vowels; represent these by C and V. There are 5 possible arrangments:
CVCVCVC
CCVCVCV
VCVCVCC
VCCVCVC
VCVCCVC
For each of these, there are 4! combination for the Cs, since they are all different, and for each of those, there are 3 arrangements for the Vs: that is the A can be first, in the middle, or last (the Es are redundant). So, there are:
5*4!*3= 5*24*3= 360. Sorry, I was off by a factor of 2 in my first calculation. I think there may be 360 total. This is a brute force method. I can't think of a better way to do it. You may want to check and verify. - Ben
Report

11/24/14

Ben B.

There are 4 consonants, and 3 vowels. I think the only combination that satisfy are:
CVCVCVC
CCVCVCV
VCVCVCC
VCCVCVC
VCVCCVC
and for each of these there are 4! possible permutations for the Cs, and for each of those, 3 unique permutations for the Vs, so this makes the total: 5*4!*3= 360. Looks like I was off by 2 before. - Ben
Report

11/24/14

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.