Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized for You
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GMAT score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
It appears that you are browsing the GMAT Club forum unregistered!
Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club
Registration gives you:
Tests
Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.
Applicant Stats
View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more
Books/Downloads
Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
some tricky PS and DS questions [#permalink]
26 Mar 2007, 14:02
This topic is locked. If you want to discuss this question please re-post it in the respective forum.
I had some difficulties solving these problems:
******************
I. A decorator bought a bolt of defective cloth that he judged to be 3/4 usable, in which case the cost would be 0.80 USD per usable yard. If it was later found that only 2/3 of the bolt could be used, what was the actual cost per usable yard?
0.60; 0.90; 1.00; 1.20; 1.70
******************
II. If x, y, and z are single-digit integers and 100(x) + 1,000 (y) + 10(z) = N, what is the units' digit of the number N?
0; 1; x; y; z
******************
III. Three stacks containing equal numbers of chips are to be made from 9 red chips, 7 blue chips, and 5 green chips. If all of these chips are used and each stack contains at least 1 chip of each color, what is the maximum number of red chips in any one stack?
7; 6; 5; 4; 3
******************
IV. What is the remainder when the positive integer x is divided by 2?
(1) x is an odd integer.
(2) x is a multiple of 3.
Re: some tricky PS and DS questions [#permalink]
26 Mar 2007, 15:09
nick_sun wrote:
I had some difficulties solving these problems:
****************** I. A decorator bought a bolt of defective cloth that he judged to be 3/4 usable, in which case the cost would be 0.80 USD per usable yard. If it was later found that only 2/3 of the bolt could be used, what was the actual cost per usable yard?
0.60; 0.90; 1.00; 1.20; 1.70
Guys. please advise/
The answer is (A).
Let's suppose that $X is the price of the bolt. The bolt size is Z yards.
Then (1) : X / (Z*3/4) = $0.8. it was expected by the decorator.
In reality he got (2) : X / (Z*2/3) = $Y. We need to find out what is the actual cost $Y per usable yard?
substitute X from (1) to (2) :
[ (Z*3/4) * 0.8 ] / [ Z*2/3 ] = $Y. Z is canceled.
Re: some tricky PS and DS questions [#permalink]
26 Mar 2007, 16:14
nick_sun wrote:
I had some difficulties solving these problems:
****************** III. Three stacks containing equal numbers of chips are to be made from 9 red chips, 7 blue chips, and 5 green chips. If all of these chips are used and each stack contains at least 1 chip of each color, what is the maximum number of red chips in any one stack?
7; 6; 5; 4; 3
Guys. please advise/
(C) : 5.
Every stack consists of the 7 chips ( 21 for the 3 stacks).
Let's assume 1 stack consists of the one blue chip, one green chip and 5 of the red ones:
BG(5R).
5 red is the maximum number.
it is impossible to insert more than 5 red chips in one stack. because the rule will be broken "each stack contains at least 1 chip of each color".
I. A decorator bought a bolt of defective cloth that he judged to be 3/4 usable, in which case the cost would be 0.80 USD per usable yard. If it was later found that only 2/3 of the bolt could be used, what was the actual cost per usable yard?
X: the judged cost by the decorator
Y: the actual cost
3/4 x = 2/3 y x = 0.8 --> y = 3/4 x 3/2 x 0.8 = 9/8 x 0.8 = 0.9
the actual cost is 0.9 USD per usavle yard
NOTE: Pi10t: you got your equation correct
3/4*0.8*(3/2) = 0.6 = Y. This should yield to 0.9 = Y.
I think you had an arithmatic error here.
the answer is B
******************
II. If x, y, and z are single-digit integers and 100(x) + 1,000 (y) + 10(z) = N, what is the units' digit of the number N?
No matter what x,y,and z are, each one of them is multiplied by 10, 100, or 1,000. Therefore, the units' digit is 0
A
If you can't visualize it, try to pick simple single-digit integers for x , y , and z and see what happens: [x=2, y=4, z=7] N = 200 + 4000 + 70 = 4270 --> units' digit of N is zero
******************
III. Three stacks containing equal numbers of chips are to be made from 9 red chips, 7 blue chips, and 5 green chips. If all of these chips are used and each stack contains at least 1 chip of each color, what is the maximum number of red chips in any one stack?
First, we have 9+7+5 = 21 chips for 3 stacks --> each stack contains 21/3 = 7 chips.
Now, since we're looking for maximum # of red chips in one stack, yet each stack must contain at least one red chip, let's use one chip only to minimize the number of red chips in two of the stacks. This will allow to maximize the number of red chips in the third stack.
Stack 1 [ the one with max. red chips ] :1 green , 1 blue , 5 red There are enough red chips such that each other stack would contain at least one red chip.
Answer is C [ 5 chips ]
******************
IV. What is the remainder when the positive integer x is divided by 2?
(1) x is an odd integer.
(2) x is a multiple of 3.
x/y = qy + r where q is the qoutient and r is the remainder
x/2 = 2q + r
Statement 1: x is odd if x is odd, then x is not divisible by 2 and the remainder r = 1 You can pick numbers to confirm this fact.
--> Statement 1 is sufficient
Statement 2: x is a multiple of 3 x could be 6 and thus r = 0 or x could be 9 and thus r = 1