Rate?

Expert replies

amirp: Senior | Next Rank: 100 Posts; Posts: 44; Joined: Sun Dec 20, 2009 2:02 pm; Thanked: 3 times

by amirp » Sat Jul 10, 2010 6:33 pm

Hi guys,

Can anyone tell me what the "Rate" of the 2nd ant is that is heading west?

Is it 7/3 inch per sec or 8/3 inch per second and why?

thanks

Attachments

Like this post

Source: Beat The GMAT — Problem Solving | Sat Jul 10, 2010 6:33 pm

grockit_andrea: GMAT Instructor; Posts: 357; Joined: Wed Aug 12, 2009 8:31 pmFollowed by: 7 members; Thanked: 128 times

by grockit_andrea » Sat Jul 10, 2010 6:52 pm

amirp wrote:Hi guys,

Can anyone tell me what the "Rate" of the 2nd ant is that is heading west?

Is it 7/3 inch per sec or 8/3 inch per second and why?

thanks

The second ant is moving at a rate of 8/3 inch per second. The first ant's rate is 2 inches per second, which can be represented as 6/3 per second. 6/3 x 1 = 6/3, and 6/3 x 1/3 = 2/3. 6/3 + 2/3 = 8/3.
You don't really need to deal with fractions to answer this, though; you can figure out pretty easily that the first ant moves 12 inches in 6 seconds, and 12 x 4/3 = 16. The legs of the triangle are therefore 12 and 16, and the hypotenuse is 20 inches, or 1 2/3 (1.67) feet.

Andrea A.
Grockit Tutor
https://www.grockit.com

Like this post

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 » Sat Jul 10, 2010 6:57 pm

amirp wrote:Hi guys,

Can anyone tell me what the "Rate" of the 2nd ant is that is heading west?

Is it 7/3 inch per sec or 8/3 inch per second and why?

thanks

1/3 faster means 4/3 of the other ant's rate: 4/3 * 2 = 8/3.

1/3 of an inch faster would mean 1/3 inch more per second than the other ant: 2 + 1/3 = 7/3.

Is the distinction clear?

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

amirp: Senior | Next Rank: 100 Posts; Posts: 44; Joined: Sun Dec 20, 2009 2:02 pm; Thanked: 3 times

by amirp » Sat Jul 10, 2010 7:00 pm

Thank you guys. got it.

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