Time distance question... Please help

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 5
Joined: Thu Aug 07, 2014 11:15 am

Time distance question... Please help

by Mary.006 » Sun Aug 17, 2014 6:39 pm
A truck travels 20 miles due north', 30 miles due east , and then 20 miles due north. How many miles is the truck from the starting point.?

20.3
70
44.7
50

User avatar
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Mon Jun 22, 2009 9:43 pm
Location: India
Thanked: 3 times
GMAT Score:770

by perwinsharma » Mon Aug 18, 2014 4:53 am
Image

Hi

This is a simple pythagorus problem.

Looking at the figures would help you explain how to approach them.

Figure 1 is the original path as traced by the question.

Figure 2 is the figure 1 reimagined to make it simpler to solve.
Praveen Sharma
Wizius Careers
Gurgaon
India
https://www.facebook.com/wiziuscareergmat/

User avatar
Legendary Member
Posts: 1100
Joined: Sat May 10, 2014 11:34 pm
Location: New Delhi, India
Thanked: 205 times
Followed by:24 members

by GMATinsight » Mon Aug 18, 2014 10:34 am
Mary.006 wrote:A truck travels 20 miles due north', 30 miles due east , and then 20 miles due north. How many miles is the truck from the starting point.?

20.3
70
44.7
50
Attachments
Solution 53.jpg
"GMATinsight"Bhoopendra Singh & Sushma Jha
Most Comprehensive and Affordable Video Course 2000+ CONCEPT Videos and Video Solutions
Whatsapp/Mobile: +91-9999687183 l [email protected]
Contact for One-on-One FREE ONLINE DEMO Class Call/e-mail
Most Efficient and affordable One-On-One Private tutoring fee - US$40-50 per hour

User avatar
Legendary Member
Posts: 1100
Joined: Sat May 10, 2014 11:34 pm
Location: New Delhi, India
Thanked: 205 times
Followed by:24 members

by GMATinsight » Mon Aug 18, 2014 10:37 am
I am afraid if you are referring to the right source of material for GMAT preparation as this question doesn't look like proper GMAT Question due to 4 Option choices given. Also it's been rare lately to expect questions of "Direction Sense" in GMAT

So word of caution are "Refer to the right source of material for GMAT preparation"
"GMATinsight"Bhoopendra Singh & Sushma Jha
Most Comprehensive and Affordable Video Course 2000+ CONCEPT Videos and Video Solutions
Whatsapp/Mobile: +91-9999687183 l [email protected]
Contact for One-on-One FREE ONLINE DEMO Class Call/e-mail
Most Efficient and affordable One-On-One Private tutoring fee - US$40-50 per hour

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Mon Aug 18, 2014 6:54 pm
Mary.006 wrote:A truck travels 20 miles due north', 30 miles due east , and then 20 miles due north. How many miles is the truck from the starting point.?

20.3
70
44.7
50
Altogether, the truck drove 40 miles north and 30 miles east.
So, 30 and 40 represent the two LEGS of a right triangle.
The truck's distance from the starting point (i.e., the hypotenuse) can be found using the Pythagorean Theorem.
30² + 40² = hypotenuse²
900 + 1600 = hypotenuse²
2500 = hypotenuse²
So, hypotenuse = 50
Answer: D


ALTERNATIVELY, we might recognize that this right triangle is an ENLARGED version of a 3-4-5 right triangle. This new right triangle is 10 TIMES as big as the 3-4-5 right triangle. So, the lengths are 30-40-50, meaning that the hypotenuse has length 50

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image