permutations and combinations

Expert replies

pranayece: Newbie | Next Rank: 10 Posts; Posts: 1; Joined: Tue Jul 21, 2015 2:38 am

by pranayece » Mon Jul 27, 2015 1:03 am

Five different roads join a village to the nearby city. The number of different ways in which a person

can go to the town and come back is:

Like this post

Source: Beat The GMAT — Problem Solving | Mon Jul 27, 2015 1:03 am

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Mon Jul 27, 2015 4:03 am

pranayece wrote:Five different roads join a village to the nearby city. The number of different ways in which a person

can go to the town and come back is:

Number of ways to travel from the city to the village = 5. (Any of the 5 roads.)
Number of ways to travel from the village back to the city = 5. (Any of the 5 roads.)
To combine these options, we multiply:
5*5 = 25.

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

Like this post

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Mon Jul 27, 2015 6:50 am

Brent Hanneson - Creator of GMATPrepNow.com

Like this post

nikhilgmat31: Legendary Member; Posts: 518; Joined: Tue May 12, 2015 8:25 pm; Thanked: 10 times

by nikhilgmat31 » Wed Jul 29, 2015 12:10 am

since he can take a same way for roundtrip.

5 * 5 = 25

if he must select a different way to return then number of ways = 5 * 4 = 20

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review