How many 4-letter words can be formed using the alphabets of

This topic has expert replies
Legendary Member
Posts: 2226
Joined: Sun Oct 29, 2017 2:04 pm
Followed by:6 members
How many 4-letter words can be formed using the alphabets of the word ENGLISH, if it is given that 4-letter word contains alphabets G and L and repetition of alphabets are not allowed?

A. 60
B. 120
C. 180
D. 200
E. 240

The OA is E

Source: e-GMAT

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sat Oct 26, 2019 6:27 am
swerve wrote:How many 4-letter words can be formed using the alphabets of the word ENGLISH, if it is given that 4-letter word contains alphabets G and L and repetition of alphabets are not allowed?

A. 60
B. 120
C. 180
D. 200
E. 240

The OA is E

Source: e-GMAT
Take the task of creating 4-letter words and break it into stages.

Stage 1: Select 2 letters from E, N, I, S, H
Since the order in which we select the two letters does not matter (yet!!), we can use combinations.
We can select 2 letters 5 letters in 5C2 ways (10 ways)
So, we can complete stage 1 in 10 ways

ASIDE: If anyone is interested, we have a video on calculating combinations (like 5C2) in your head below

Stage 2: Combine G and L with the two letters you chose in stage 1, and then arrange those 4 letters
We can arrange n objects in n! ways
So, we can arrange the 4 letters in 4! ways (= 24 ways)
We can complete stage 2 in 24 ways

By the Fundamental Counting Principle (FCP), we can complete the two stages (and thus create 4-letter words) in (10)(24) ways (= 240 ways)

Answer: E

Note: the FCP can be used to solve the MAJORITY of counting questions on the GMAT. So, be sure to learn it.
Brent Hanneson - Creator of GMATPrepNow.com
Image

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Sat Oct 26, 2019 1:06 pm
swerve wrote:How many 4-letter words can be formed using the alphabets of the word ENGLISH, if it is given that 4-letter word contains alphabets G and L and repetition of alphabets are not allowed?

A. 60
B. 120
C. 180
D. 200
E. 240
Number of options for G = 4. (Any of the 4 positions in the word.)
Number of options for L = 3. (Any of the 3 remaining positions in the word.)
Number of options for the next position in the word = 5. (Any of the 5 remaining letters.)
Number of options for the last position in the word = 4. (Any of the 4 remaining letters.)
To combine these options, we multiply:
4*3*5*4 = 240

The correct answer is E.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7243
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Tue Oct 29, 2019 6:40 pm
swerve wrote:How many 4-letter words can be formed using the alphabets of the word ENGLISH, if it is given that 4-letter word contains alphabets G and L and repetition of alphabets are not allowed?

A. 60
B. 120
C. 180
D. 200
E. 240

The OA is E

Source: e-GMAT
Since G and L must be used, the number of ways of choosing 2 more letters from the remaining 5 is 5C2 = (5 x 4)/2 = 10. However, once we have 4 letters, there are 4! = 24 ways to arrange them. Therefore, there are a total of 10 x 24 = 240 words that can be formed.

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage