• NEW! FREE Beat The GMAT Quizzes
Hundreds of Questions Highly Detailed Reporting Expert Explanations
• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn
100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## Donna has a 60 miles drive to a work conference... tagged by: AAPL ##### This topic has 2 expert replies and 0 member replies ### Top Member ## Donna has a 60 miles drive to a work conference... Donna has a 60 miles drive to a work conference. She begins driving at 30 miles per hour, but halfway through the drive, she realizes she is going to be late and speed up. How fast should she drive the remaining distance (in miles per hour) if she needs to complete the entire trip in 90 minutes? A. 55 B. 60 C. 65 D. 70 E. 88 The OA is B. We know that the total distance is 60 miles and the total time that she needs to complete the entire trip is 90 minutes or 1.5 hours. She drove the first 30 miles in an hour because she begins driving at 30 miles per hour, that's mean that the remaining distance is 30 miles. Then, she will drive the last 30 miles at a rate of, speed = 30 miles / 0.5 hours = 60 miles per hour to complete the trip in 90 minutes. Is there another strategic approach to solve this PS question? Can any experts help, please? Thanks. ### GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 AAPL wrote: Donna has a 60 miles drive to a work conference. She begins driving at 30 miles per hour, but halfway through the drive, she realizes she is going to be late and speed up. How fast should she drive the remaining distance (in miles per hour) if she needs to complete the entire trip in 90 minutes? A. 55 B. 60 C. 65 D. 70 E. 88 The OA is B. We know that the total distance is 60 miles and the total time that she needs to complete the entire trip is 90 minutes or 1.5 hours. She drove the first 30 miles in an hour because she begins driving at 30 miles per hour, that's mean that the remaining distance is 30 miles. Then, she will drive the last 30 miles at a rate of, speed = 30 miles / 0.5 hours = 60 miles per hour to complete the trip in 90 minutes. Is there another strategic approach to solve this PS question? Can any experts help, please? Thanks. Hi AAPL. Let's take a look. We know she has to drive 60 miles in 90 minutes. Now, we are asked for miles per HOUR. Hence, let's make the conversion from minutes to hours. Therefore, 90 minutes = 90/60 = 1.5 hours. Now, Donna drove halfway at 30 miles per hour, this implies that she drove 60/2 = 30 miles at 30 miles per hour. That is to say, that she has driven for ONE hour. Now, if she wants to arrive on time, she has to drive 30 miles in 1.5 - 1 = 0.5 hours. This implies that she has to drive at $$30\ miles\ =\ V\cdot0.5\ hours\ \Leftrightarrow\ V=60\ miles\ per\ hour.$$ So, the correct answer is the option B. I hope this answer can help you. I'm available if you'd like a follow-up. Regards. _________________ GMAT Prep From The Economist We offer 70+ point score improvement money back guarantee. Our average student improves 98 points. Free 7-Day Test Prep with Economist GMAT Tutor - Receive free access to the top-rated GMAT prep course including a 1-on-1 strategy session, 2 full-length tests, and 5 ask-a-tutor messages. Get started now. ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 2950 messages Followed by: 19 members Upvotes: 43 AAPL wrote: Donna has a 60 miles drive to a work conference. She begins driving at 30 miles per hour, but halfway through the drive, she realizes she is going to be late and speed up. How fast should she drive the remaining distance (in miles per hour) if she needs to complete the entire trip in 90 minutes? A. 55 B. 60 C. 65 D. 70 E. 88 The first 30 miles take 30/30 = 1 hour. She needs to complete the next 30 miles in 3/2 - 1 = 1/2 hour. So she must drive at a rate of 30/(1/2) = 60 miles per hour. Answer: B _________________ Scott Woodbury-Stewart Founder and CEO scott@targettestprep.com See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to \$200

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• 5-Day Free Trial
5-day free, full-access trial TTP Quant

Available with Beat the GMAT members only code

### Top First Responders*

1 Ian Stewart 41 first replies
2 Brent@GMATPrepNow 40 first replies
3 Scott@TargetTestPrep 39 first replies
4 Jay@ManhattanReview 32 first replies
5 GMATGuruNY 26 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

159 posts
2 Max@Math Revolution

Math Revolution

92 posts
3 Brent@GMATPrepNow

GMAT Prep Now Teacher

60 posts
4 Ian Stewart

GMATiX Teacher

50 posts
5 GMATGuruNY

The Princeton Review Teacher

37 posts
See More Top Beat The GMAT Experts