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

Redeem

Second-degree equations

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 30
Joined: Tue Sep 29, 2009 7:04 pm
Thanked: 1 times

Second-degree equations

by pullagurla » Thu Sep 02, 2010 10:34 pm
Amount of Bacteria Present
Time Amount
1:00 P.M. 10.0 grams
4:00 P.M. x grams
7:00 P.M. 14.4 grams

Data for a certain biology experiment are given in
the table above. If the amount of bacteria present
increased by the same factor during each of the two
3-hour periods shown, how many grams of bacteria
were present at 4:00 P.M. ?
(A) 12.0
(B) 12.1
(C) 12.2
(D) 12.3
(E) 12.4

Explain by picking numbers !
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Fri Sep 03, 2010 3:52 am
Let us start from option (A), let us assume 12 gms of bacteria were present at 4 PM and the amount of bacteria present be increased by factor, f.
From 1 PM to 4 PM, the bacteria increases by f. So, 10 * f = 12 implies f = 1.2
Similarly from 4 PM to 7 PM, bacteria increases by f. So, 12 * f = 14.4 implies f = 1.2 again.
Since f is the same that is 1.2 from in both the time intervals, so x = 12 gms is the right choice

The correct answer is [spoiler](A)[/spoiler].
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Post new topic Post Reply
• Page 1 of 1