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

Redeem

Rounding off

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 56
Joined: Tue Mar 31, 2009 12:17 am
GMAT Score:750+

Rounding off

by ILULA08 » Tue Aug 11, 2009 8:32 pm
Q37:
If an automobile averaged 22.5 miles per gallon of gasoline, approximately how many kilometers per liter of gasoline did the automobile average? (1 mile = 1.6 kilometers and 1 gallon = 3.8 liters, both rounded to the nearest tenth.)
A. 3.7
B. 9.5
C. 31.4
D. 53.4
E. 136.8

Note: As you can see this problem is very easy but I got confused about this rounding to nearest 10th or 100th. If someone can explain me that, I would really be grateful to him.

Thanks in anticipation :)
Top
Source: — Problem Solving |
Legendary Member
Posts: 752
Joined: Sun May 17, 2009 11:04 pm
Location: Tokyo
Thanked: 81 times
GMAT Score:680

by tohellandback » Tue Aug 11, 2009 9:16 pm
22.5 miles per gallon
when you convert the values in kilometers and litres

22.5* 1.6/3.8= 22.5/(something a little more than 2)= something a little less than 11.25
answer B
The powers of two are bloody impolite!!
Top
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Tue Aug 11, 2009 7:33 am

by sureshsef » Tue Aug 11, 2009 9:48 pm
OA is b.

(22.5 x 1.6 )/ 3.8

= 9.5
Top
Master | Next Rank: 500 Posts
Posts: 156
Joined: Sat Jul 19, 2008 6:41 am
Thanked: 8 times

Easy method

by enniguy » Tue Aug 11, 2009 11:00 pm
Try this problem this way. The moment I looked at 22.5, I multiplied it by 2. I got 45. I multiplied it by another 2 just to get a multiple of 10 on top.

So the question became,

(90/4) * (1.6 / 3.8 )

= (90/4) * (16 / 38)

Canceling 4 and 16,

= 90 * 4 / 38.

Approximately cancel 38 as, 10 times 4. Then you are left with 90 / 10.

Approx. answer is 9 something. 9.5 in this case.
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8085
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Tue Feb 27, 2018 10:50 am
ILULA08 wrote:Q37:
If an automobile averaged 22.5 miles per gallon of gasoline, approximately how many kilometers per liter of gasoline did the automobile average? (1 mile = 1.6 kilometers and 1 gallon = 3.8 liters, both rounded to the nearest tenth.)
A. 3.7
B. 9.5
C. 31.4
D. 53.4
E. 136.8
22.5 miles is 22.5 x 1.6 = 36 km.

1 gallon is 3.8 liters.

So the approximate rate, in km/liter, is 36/3.8 = 9.473.

Answer: B

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
Post new topic Post Reply
• Page 1 of 1