## A gang of criminals hijacked a train heading due south. At exactly the same time, a police car located 50 miles north of

##### This topic has expert replies
Legendary Member
Posts: 1918
Joined: 29 Oct 2017
Followed by:6 members

### A gang of criminals hijacked a train heading due south. At exactly the same time, a police car located 50 miles north of

by swerve » Thu Apr 15, 2021 4:52 am

00:00

A

B

C

D

E

## Global Stats

A gang of criminals hijacked a train heading due south. At exactly the same time, a police car located 50 miles north of the train started driving south toward the train on an adjacent roadway parallel to the train track. If the train traveled at a constant rate of 50 miles per hour, and the police car traveled at a constant rate of 80 miles per hour, how long after the hijacked did the police car catch up with the train?

A. 1 hour
B. 1 hour and 20 minutes
C. 1 hour and 40 minutes
D. 2 hours
E. 2 hours and 20 minutes

The OA is C

Source: Manhattan Prep

### GMAT/MBA Expert

GMAT Instructor
Posts: 15463
Joined: 08 Dec 2008
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1266 members
GMAT Score:770

### Re: A gang of criminals hijacked a train heading due south. At exactly the same time, a police car located 50 miles nort

by [email protected] » Fri Apr 16, 2021 5:12 am
swerve wrote:
Thu Apr 15, 2021 4:52 am
A gang of criminals hijacked a train heading due south. At exactly the same time, a police car located 50 miles north of the train started driving south toward the train on an adjacent roadway parallel to the train track. If the train traveled at a constant rate of 50 miles per hour, and the police car traveled at a constant rate of 80 miles per hour, how long after the hijacked did the police car catch up with the train?

A. 1 hour
B. 1 hour and 20 minutes
C. 1 hour and 40 minutes
D. 2 hours
E. 2 hours and 20 minutes

The OA is C

Source: Manhattan Prep
This is a shrinking gap question.

Train's speed = 50 miles per hour
Police card's speed = 80 miles per hour
80 miles per hour - 50 miles per hour = 30 miles per hour
So, the gap between the train and the police car DECREASES at a rate of 30 miles per hour

Original gap (aka distance) = 50 miles
Time = distance/rate
So, time to close gap = 50/30 hours
= 5/3 hours
= 1 2/3 hours
= 1 hour and 40 minutes