BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Marcia took a trip consisting of three segments at three

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 2898
Joined: Thu Sep 07, 2017 2:49 pm
Thanked: 6 times
Followed by:5 members

Marcia took a trip consisting of three segments at three

by Vincen » Tue Feb 13, 2018 3:43 am
Marcia took a trip consisting of three segments at three different speeds: she drove a distance of (5D) at a speed of (2v), then a distance of (4D) at a speed of (3v), then a distance of D at a speed of (6v). In terms of D and v, what was the total time of Marcia's trip?

(A) 4D/v
(B) 4v/D
(C) (10D)/(11v)
(D) (10v)/(11D)
(E) (11D)/(10v)

The OA is the option A.

How can I find the correct answer? Should I add all the distances and the speeds? I am confused. Experts, I need your help. <i class="em em-neutral_face"></i>
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
Legendary Member
Posts: 503
Joined: Thu Jul 20, 2017 9:03 am
Thanked: 86 times
Followed by:15 members
GMAT Score:770

by ErikaPrepScholar » Tue Feb 13, 2018 6:34 am
Hey Vincen,

We need to consider each segment of the trip separately.

We know that distance = rate * time. Rearranged, this gives us time = distance / rate. So for each segment of the trip, we should be able to divide the distance by the rate (speed) to give the time. Then, we can add together the time for the three segments to give the total time of the trip.

Segment 1: 5D / 2v
Segment 2: 4D / 3v
Segment 3: D / 6v

Adding the three together gives:
$$\frac{5D}{2v}+\frac{4D}{3v}+\frac{D}{6v}$$
Finally, we find a common denominator (6v) and simplify:
$$\frac{5D\left(3\right)}{2v\left(3\right)}+\frac{4D\left(2\right)}{3v\left(2\right)}+\frac{D}{6v}$$ $$\frac{15D}{6v}+\frac{8D}{6v}+\frac{D}{6v}$$ $$\frac{24D}{6v}=\frac{4D}{v}$$
So the correct answer is A.
Image

Erika John - Content Manager/Lead Instructor
https://gmat.prepscholar.com/gmat/s/

Get tutoring from me or another PrepScholar GMAT expert: https://gmat.prepscholar.com/gmat/s/tutoring/

Learn about our exclusive savings for BTG members (up to 25% off) and our 5 day free trial

Check out our PrepScholar GMAT YouTube channel, and read our expert guides on the PrepScholar GMAT blog
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8083
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Wed Feb 14, 2018 10:17 am
Vincen wrote:Marcia took a trip consisting of three segments at three different speeds: she drove a distance of (5D) at a speed of (2v), then a distance of (4D) at a speed of (3v), then a distance of D at a speed of (6v). In terms of D and v, what was the total time of Marcia's trip?

(A) 4D/v
(B) 4v/D
(C) (10D)/(11v)
(D) (10v)/(11D)
(E) (11D)/(10v)
The time for her first leg of the trip is 5D/(2v).

The time for her second leg is 4D/(3v).

The time for her last leg is: D/(6v).

Thus the total time is:

5D/(2v) + 4D/(3v) + D/(6v)

15D/(6v) + 8D/(6v) + D/(6v)

24D/(6v)

4D/v

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top

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] » Wed Feb 14, 2018 2:49 pm
Hi Vincen,

We're told that Marcia took a trip consisting of 3 segments at three different speeds: she drove a distance of (5D) at a speed of (2V), then a distance of (4D) at a speed of (3V), then a distance of D at a speed of (6V). We're asked for the total TIME of Marcia's trip in terms of D and V. This question can be solved by TESTing VALUES.

IF.... D=6 and V=1
1st Leg --> 30 miles at 2 miles/hour = 15 hours
2nd Leg --> 24 miles at 3 miles/hour = 8 hours
3rd Leg --> 6 miles at 6 miles/hour = 1 hour

Total Time = 15 + 8 + 1 = 24 hours. So we're looking for an answer that equals 24 when we TEST D=6 and V=1. There's only one answer that matches...

Final Answer: A

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Post new topic Post Reply
• Page 1 of 1