Two long time friends want to meet for lunch on a free weeke

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 187
Joined: Tue Sep 13, 2016 12:46 am
Two long time friends want to meet for lunch on a free weekend. One friend Ann, lives in Portland, and the other, Bill, lives in Seattle. They decide to meet somewhere on the 200-mile stretch connecting the two cities, and they start driving simultaneously from their respective cities toward each other along the same route. Ann drives an average of 50 miles per hour, and Bill drives an average of 70 miles per hour. Approximately how many miles from Portland will the two meet?

a) 56.7
b) 60.0
c) 72.5
d) 83.3
e) 96.7

Please assist with above problem.

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Tue Oct 18, 2016 9:50 pm
Hi alanforde800Maximus,

This is an example of a combined rate question. Since Ann drives at 50 miles/hour and Bill drives at 70 miles/hour, they travel a total of 120 miles each hour. The starting distance between them is 200 miles, so we can figure out how long it would take them to meet up...

D = (R)(T)
200 miles = (120 miles/hour)(Time)
200/120 = Time
5/3 hours = Time to meet

The questions how far they are from PORTLAND when they meet. Since Anne is traveling from Portland, and they meet after 5/3 hours, we can figure out how far Anne is from Portland...

D = (R)(T)
D = (50 miles/hour)(5/3 hours)
D = 250/3 miles
D = 83.33333 miles

Final Answer: D

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image

User avatar
Master | Next Rank: 500 Posts
Posts: 157
Joined: Mon Aug 16, 2010 7:30 pm
Location: India
Thanked: 65 times
Followed by:3 members

by crackverbal » Wed Oct 19, 2016 3:29 am
Hi alanforde800Maximus,

Another approach of solving Speed, Distance and Time questions is to figure out which one out of distance and time will be a constant (in most cases there will be one).

If the distance is constant then we use the equation S1T1 = S2T2

If the time is constant then we use the equation D1/S1 = D2/S2

Another good practice to follow is to always graphically represent the question as shown in the image.

Image

Since the time is constant here

D(A)/S(A) = D(B)/S(B)
x/50 = (200-x)/70 -----> x = 83.3
Join Free 4 part MBA Through GMAT Video Training Series here -
https://gmat.crackverbal.com/mba-throug ... video-2018

Enroll for our GMAT Trial Course here -
https://gmatonline.crackverbal.com/

For more info on GMAT and MBA, follow us on @AskCrackVerbal

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 » Wed Oct 19, 2016 4:16 am
alanforde800Maximus wrote:Two long time friends want to meet for lunch on a free weekend. One friend Ann, lives in Portland, and the other, Bill, lives in Seattle. They decide to meet somewhere on the 200-mile stretch connecting the two cities, and they start driving simultaneously from their respective cities toward each other along the same route. Ann drives an average of 50 miles per hour, and Bill drives an average of 70 miles per hour. Approximately how many miles from Portland will the two meet?

a) 56.7
b) 60.0
c) 72.5
d) 83.3
e) 96.7
Ann and Bill are WORKING TOGETHER to cover the 200 miles between them.
When people work together, ADD THE RATES.
The combined rate for Ann and Bill = 50+70 = 120 miles per hour.
Of every 120 miles traveled when Ann and Bill work together, Ann drives 50 miles.
Thus, she will travel 50/120 of the 200 miles:
(50/120)(200) = 83.33 miles.

The correct answer is D.
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