An ant is clinging to one corner of a box in the shape of a cube. The ant wants to get to the most distant corner of the box by crawling only along the edges of the cube and without ever revisiting a place it has been. How many different paths can the ant take to the most distant corner?
A. 6
B. 12
C. 18
D. 24
E. 30
The OA is C.
Please, can anyone assist me with this PS question? I'm confused. Thanks in advance.
An ant is clinging to one corner of a box in the shape of a
This topic has expert replies
-
- Moderator
- Posts: 2209
- Joined: Sun Oct 15, 2017 1:50 pm
- Followed by:6 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
-
- Legendary Member
- Posts: 2898
- Joined: Thu Sep 07, 2017 2:49 pm
- Thanked: 6 times
- Followed by:5 members
Hello BTGmoderatorLU.
I will give you an answer using the image of a cube with the vertex A, B, C, D, E, F, G, H.
Let's suppose the ant starts in the vertex A and it wants to arrive to the vertex G.
Now, the ways the ant can go are:
In 3 steps:
1. A-B-C-G
2. A-D-C-G
3. A-B-F-G
4. A-D-H-G
5. A-E-F-G
6. A-E-H-G
In 5 steps:
7. A-B-F-E-H-G
8. A-D-H-E-F-G
9. A-B-C-D-H-G
10. A-D-C-B-F-G
11. A-E-F-B-C-G
12. A-E-H-D-C-G
In 7 steps:
13. A-B-C-D-H-E-F-G
14. A-D-C-B-F-E-H-G
15. A-E-F-B-C--D-H-G
16. A-E-H-D-C--B-F-G
17. A-B-F-E-H-D-C-G
18. A-D-H-E-F-B-C-G
These are all the possible paths the ant can make to go from vertex A to vertex G. Therefore, the correct answer is the option [spoiler]C=18[/spoiler]
I hope it can help you.
I'd like to see an algebraic solution. <i class="em em-smiley"></i>
I will give you an answer using the image of a cube with the vertex A, B, C, D, E, F, G, H.
Let's suppose the ant starts in the vertex A and it wants to arrive to the vertex G.
Now, the ways the ant can go are:
In 3 steps:
1. A-B-C-G
2. A-D-C-G
3. A-B-F-G
4. A-D-H-G
5. A-E-F-G
6. A-E-H-G
In 5 steps:
7. A-B-F-E-H-G
8. A-D-H-E-F-G
9. A-B-C-D-H-G
10. A-D-C-B-F-G
11. A-E-F-B-C-G
12. A-E-H-D-C-G
In 7 steps:
13. A-B-C-D-H-E-F-G
14. A-D-C-B-F-E-H-G
15. A-E-F-B-C--D-H-G
16. A-E-H-D-C--B-F-G
17. A-B-F-E-H-D-C-G
18. A-D-H-E-F-B-C-G
These are all the possible paths the ant can make to go from vertex A to vertex G. Therefore, the correct answer is the option [spoiler]C=18[/spoiler]
I hope it can help you.
I'd like to see an algebraic solution. <i class="em em-smiley"></i>
- GMATGuruNY
- 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
Let the initial vertex = A, implying that the ant must travel to G.
Let's divide the journey into 3 stages and count the number of options for each stage.
First stage;
Since the ant can travel from A to B, D, or E, the number of options for the first stage = 3.
Second stage:
Whether the ant is at B, D or E, it has 2 options for the next stage.
If the ant is at B, it can travel next to F or C.
If the ant is at D, it can travel next to C or H.
If the ant is at E, it can travel next to F or H.
Thus:
The number of options for the second stage = 2.
Third stage:
Wherever the ant ends in the second stage, it can then travel to G by a short route, a medium route, or a long route, for a total 3 options.
For example:
If the ant travels A-B-F in the first 2 stages, it can then travel to G as follows:
Short route = F-G.
Medium route = F-E-H-G.
Long route = F-E-H-D-C-G.
Thus:
The number of options for the third stage = 3.
To combine the options for each stage, we multiply:
3*2*3 = 18.
The correct answer is C.
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
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
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7245
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
BTGmoderatorLU wrote:An ant is clinging to one corner of a box in the shape of a cube. The ant wants to get to the most distant corner of the box by crawling only along the edges of the cube and without ever revisiting a place it has been. How many different paths can the ant take to the most distant corner?
A. 6
B. 12
C. 18
D. 24
E. 30
Let's say the ant is currently at corner A, thus it wants to go to corner G since it's the furthest from A.
Now from A, its next move is to B, to E, or to D. Let's analyze the number of paths it can have if its next move is to B:
A-B-F-G
A-B-F-E-H-G
A-B-F-E-H-D-C-G
A-B-C-G
A-B-C-D-H-G
A-B-C-D-H-E-F-G
We see that we have 6 paths if its first move is to B. Without listing the actual paths, if its first move is to E, there should be also 6 paths, and another 6 paths if its first move is to D. Therefore, there will be a total of 6 + 6 + 6 = 18 different paths from A to G.
Answer: C
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews