GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 19 Apr 2019, 07:39

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# A race car driver has to drive from the intersection A to in

Author Message
TAGS:

### Hide Tags

Manager
Affiliations: The Earth organization, India
Joined: 25 Dec 2010
Posts: 185
WE 1: SAP consultant-IT 2 years
WE 2: Entrepreneur-family business 2 years
A race car driver has to drive from the intersection A to in  [#permalink]

### Show Tags

03 Jun 2011, 09:23
1
00:00

Difficulty:

55% (hard)

Question Stats:

50% (01:39) correct 50% (02:06) wrong based on 28 sessions

### HideShow timer Statistics

A race car driver has to drive from the intersection A to intersection B along the route that is confined to the square grid of four touchstones and three avenues shown in the map above. How many routes from A to B can the racer take that have minimum possible length?

A. 7
B. 9
C. 10
D. 14
E. 18

http://s3.amazonaws.com/production.grockit.com/content_images/production/1264222415/40_a.jpg

cant we solve this by combinatorics ? grockit gives solution via counting which is cumbersome.

Attachment:

40_a.jpg [ 9.39 KiB | Viewed 236 times ]

_________________
Cheers !!

Quant 47-Striving for 50
Verbal 34-Striving for 40
Retired Moderator
Joined: 20 Dec 2010
Posts: 1784
Re: A race car driver has to drive from the intersection A to in  [#permalink]

### Show Tags

03 Jun 2011, 09:37
bblast wrote:
A race car driver has to drive from the intersection A to intersection B along the route that is confined to the square grid of four touchstones and three avenues shown in the map above. How many routes from A to B can the racer take that have minimum possible length?

7
9
10
14
18

http://s3.amazonaws.com/production.grockit.com/content_images/production/1264222415/40_a.jpg

cant we solve this by combinatorics ? grockit gives solution via counting which is cumbersome.

Count the number of columns, say c
Count the number of rows, say r

$$Ways = C^{(c+r)}_{c}$$
OR
$$Ways = C^{(c+r)}_{r}$$

In this figure,
c=2
r=3
c+r=5
$$Ways = C^{5}_{3} = 10$$

Ans: "C"
**************************************************
_________________
Manager
Joined: 04 Apr 2010
Posts: 132
Re: A race car driver has to drive from the intersection A to in  [#permalink]

### Show Tags

03 Jun 2011, 09:51
1
UUULL (shortest possible way includes 3 UPs and 2 Lefts)
No. of arrangement includes = 5! / (3! * 2!) = 10
_________________
Consider me giving KUDOS, if you find my post helpful.
If at first you don't succeed, you're running about average. ~Anonymous
Non-Human User
Joined: 09 Sep 2013
Posts: 10554
Re: A race car driver has to drive from the intersection A to in  [#permalink]

### Show Tags

11 Apr 2019, 10:59
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: A race car driver has to drive from the intersection A to in   [#permalink] 11 Apr 2019, 10:59
Display posts from previous: Sort by