Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Bacteria

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Legendary Member
Posts: 2789
Joined: Tue Jul 26, 2011 12:19 amFollowed by: 43 members
Location: Chennai, India
Thanked: 206 times
GMAT Score:640
by GmatKiss » Mon Oct 31, 2011 11:52 pm
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
You do not have the required permissions to view the files attached to this post.
Last edited by GmatKiss on Tue Nov 01, 2011 12:08 am, edited 1 time in total.
Top
Join the discussion
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 516
Joined: Fri Jul 31, 2009 3:22 pmFollowed by: 13 members
Thanked: 112 times

by smackmartine » Tue Nov 01, 2011 12:01 am
GmatKiss wrote: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
I don't see any table.
Smack is Back ...
It takes time and effort to explain, so if my comment helped you please press Thanks button :)
Top
Join the discussion
Legendary Member
Posts: 2789
Joined: Tue Jul 26, 2011 12:19 amFollowed by: 43 members
Location: Chennai, India
Thanked: 206 times
GMAT Score:640

by GmatKiss » Tue Nov 01, 2011 12:09 am
smackmartine wrote:
GmatKiss wrote: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
I don't see any table.
Sorry !! Attached it now..
Top
Join the discussion
Legendary Member
Posts: 966
Joined: Sat Jan 02, 2010 8:06 amFollowed by: 21 members
Thanked: 230 times

by shankar.ashwin » Tue Nov 01, 2011 12:13 am
10 to 12 (20% growth)
12 to 14.4 (20% growth)
A Think of it as a compound interest problem.
Top
Join the discussion
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Tue Nov 01, 2011 3:07 am
GmatKiss wrote: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
We can plug in the answers, which represent the number of bacteria at 4pm.
We should start with A, the only integer value.

Answer choice A: 12
7pm/4pm = 14.4/12 = 144/120 = 6/5.
4pm/1pm = 12/10 = 6/5.
Success!

The correct answer is A.

We could also set up the following proportion:
7pm/4pm = 4pm/1pm
14.4/x = x/10
x² = 144
x = 12.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
User avatar
Master | Next Rank: 500 Posts
Posts: 425
Joined: Wed Dec 08, 2010 9:00 amFollowed by: 7 members
Thanked: 56 times
GMAT Score:690

by LalaB » Tue Nov 01, 2011 9:39 pm
if u need a formula, please see below (it is from mgmat guide book)-


(Original amount)*(factor)^t/s=future amount or

10*factor^(7-1)/3=14.4

factor=1.20

where (7-1) is time difference between 7.00 p.m. and 1.00 p.m. ; 3 expresses that every 3 hours the amount changes (4.00p.m.-1.00 p.m.=3 and 7.00 p.m.-4.00 p.m.=3).


so X = 10 *1.20=12

A is the answ
Top
Join the discussion