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

Redeem

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.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
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
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start 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 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Need hel solving some problem from Gmatprep.....thanks:)

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 41
Joined: Tue Dec 16, 2008 11:53 pm
by billyr » Thu Feb 12, 2009 8:43 am
Q1: A company has two type of machine R and S. Operating at constant rate, R does the job in 36 hr, s does the same job in 18 hr. If the company use the same number of each type of machine to do job in 2 hr, how many machine type r used?
a)2
b)4
c)6---->answer
d)10
e)12


Q2: If 2^x - 2^x-2= 3(12^13) what is the value of x?
a)9
b)11
c)13
d)15------->answer
e)17

Q3: For every positive even integer n, the function h(n) is defined to be the product of all even integers from 2 to n, inclusive. If P is the smallest prime factor of h(100)+1, then p is?

a)between 2 and 10
b)between 10 and 20
c)between 20 and 30
d)between 30 and 40
e)greater than 40--------> answer


Q4:If n is a positive integer and the product of all the integer from 1 to n inclusive is a multiple of 990, what is the least possible value for n?
a)10
b)11------>answer
c)12
d)13
e)15



Data sufficiency:
Q5: What is the tenth digit of positive integer r?

(1) the tens digit of r/10 is 3

(2)the hundred digit of 10r is 6


The answer is B (statement 2 alone sufficient) but i totally lost about that.


Q6:If x&y are positive integer, what value is xy?

(1)the greatest common factor x&y is 10

(2)the least common multiple of x& y is 180


the answer is C(Both statement is sufficient)----but i don't know how.





Thanks a lot
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Quantitative Reasoning |
Senior | Next Rank: 100 Posts
Posts: 76
Joined: Sat Jan 24, 2009 3:00 pm
Thanked: 11 times
GMAT Score:730

by BuckeyeT » Thu Feb 12, 2009 9:04 am
Just a reminder that you should try to post only 1 question in a post. It might increase the number of responses.

I can take a quick stab at #1, and I might be able to look at the others later.

1. This is a work problem. R = 1/36, S = 1/18.
R + S = hours to complete job inverted
1/36 + 1/18 = 3/36 = 1/12 or 12 hours to complete the job together.
If it takes them 12 hours together, and you need it done in 2 hours, then
12/2 = 6 times faster or 6 pairs of R and S.
So, the number of R machines = 6.

C.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 76
Joined: Sat Jan 24, 2009 3:00 pm
Thanked: 11 times
GMAT Score:730

by BuckeyeT » Thu Feb 12, 2009 9:11 am
I'm assuming Q2 is written incorrectly...

Q2: If 2^x - 2^x-2= 3(2^13) what is the value of x?

Start factoring:
2^x - 2^(x-2) can be factored into...
2^(x-2) * (2^2 - 1) or...
2^(x-2) * (4-1) ...
2^(x-2) * 3

Look back at the equivalency...
2^(x-2) * 3 = 3(2^13) divide both sides by 3...
2^(x-2) = 2^13 ...
So, x-2 = 13...
x = 15

Answer D.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 76
Joined: Sat Jan 24, 2009 3:00 pm
Thanked: 11 times
GMAT Score:730

by BuckeyeT » Thu Feb 12, 2009 11:56 am
Q4:If n is a positive integer and the product of all the integer from 1 to n inclusive is a multiple of 990, what is the least possible value for n?

To be a multiple of 990, you have at least the same factors are 990. So, let's look at the factors of 990.
990 = 2*495
=2*5*99
=2*5*11*9
=2*5*11*3*3

Since we have know that the greatest prime factor is 11, we know that n has to go through at LEAST n=11 to remain true. Therefore, 11 is the least possible value of n in order for 1*2*...*n to be a multiple of 990.

Q5: What is the tens digit of positive integer r?

(1) the tens digit of (r/10) is 3.
Let's assume, (r/10) = 30.
r = 10*30
r = 300
The tens place is 0. But, we need it to be consistent.
Let's assume, (r/10) = 88.
r = 10*88
r = 880
The tens place is 8. Therefore, we proved this statement insuffient because it's not the same for all r.

(2) The hundreds digit of 10r is 6.
Let's assume, 10r = 600.
r = 600/10
r = 60
The tens place is 6. But, we need it to be consistent.
Let's assume, 10r = 694.
r = 694/10
r = 69.4
The tens place is 6. And, you'll notice it will happen for all others. Therefore, this statement is sufficient.

Answer B.

The much easier way to look at this question is just to determine which way the decimal point will shift (and how that impacts the tens place). No calculation should be necessary.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1