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:
Re: Plz help to solve this ps [#permalink]
11 Dec 2009, 18:56
2)
The first digit can only be 8 or 9.
If it is 8, the second digit can assume 9 values, 5 of which are odd and 4 of which are even. The third digit must be odd, hence it can assume 5 values at the most. If the second digit is even, we can pick any of these 5 values, hence we have 4(#of suitable even second digits)*5(#number of suitable odd third digits)=20. If the second digit is odd, the third has still to be odd, but it cannot assume the same value as the second, hence we have 5(#of suitable odd second digits)*4(# of suitable odd third digits)=20. The total in the 800-899 range is 40.
If the first digit is 9, the second digit can assume 4 even values and 5 odd values. If the second digit is even, the third digit can be any odd digit but 9, hence we have 5(# of suitable even second digits)*4(# of suitable odd third digits)=20. If the second digit is odd, the third digit cannot be 9 or equal to the second digit, and it still has to be odd, hence 4(# of suitable odd second digits)*3(# of suitable odd third digits)=12. The total in the 900-999 range is 32.
The total number of odd numbers with different digits above 800 is then 72.
Re: Plz help to solve this ps [#permalink]
12 Dec 2009, 05:26
Expert's post
ans for 1) 200... take 4 cases where both x n y are +,both -, and two cases where each are opposite to each other... ull get a square with sides given by <(0,10)(10,0)> ,<(0,-10)(10,0)> , <(0,10)(-10,0)> and <(0,-10)(10,0)>... the diag of sq will be 10+10=20...so each side is 10(2)^1/2.... 2)
kp1811 wrote:
raghavs wrote:
tricky ps
If a circle is inscribed in a square, then the area outside the circle is what percent of the total area of the square (approximately)?
14% 18% 22% 28% 30%
let side of square be 2a then radius of circle will be a. Area of square = 4a^2 and Area of Circle = πa^2
So area outside circle is 4a^2 - πa^2
% of area outside = (4a^2 - πa^2)/a^2 *100 = 22% approx.
shud be 18%... as mentioned above but while dividing it has to be 4a^2 and not a^2 3) 72.... _________________
Re: Plz help to solve this ps [#permalink]
10 Jan 2010, 19:55
chetan2u wrote:
ans for 1) 200... take 4 cases where both x n y are +,both -, and two cases where each are opposite to each other... ull get a square with sides given by <(0,10)(10,0)> ,<(0,-10)(10,0)> , <(0,10)(-10,0)> and <(0,-10)(10,0)>... the diag of sq will be 10+10=20...so each side is 10(2)^1/2.... 2)
kp1811 wrote:
raghavs wrote:
tricky ps
If a circle is inscribed in a square, then the area outside the circle is what percent of the total area of the square (approximately)?
14% 18% 22% 28% 30%
let side of square be 2a then radius of circle will be a. Area of square = 4a^2 and Area of Circle = πa^2
So area outside circle is 4a^2 - πa^2
% of area outside = (4a^2 - πa^2)/a^2 *100 = 22% approx.
shud be 18%... as mentioned above but while dividing it has to be 4a^2 and not a^2 3) 72....
Hi.. plz help me with this calculation..
% of area outside = (4a^2 - πa^2)/4a^2 *100 = 18% , how do you calculate this to get 18%
Re: Plz help to solve this ps [#permalink]
12 Jan 2010, 17:34
Expert's post
\(|\frac{x}{2}| + |\frac{y}{2}| = 5\)
After solving you'll get equation of four lines:
\(y<0\) and \(x<0\) --> \(y=-10-x\) \(y>0\) and \(x<0\) --> \(y=10+x\) \(y>0\) and \(x>0\) --> \(y=10-x\) \(y<0\) and \(x>0\) --> \(y=x-10\)
If you draw these four lines (line segments) you'll see that the figure (square) which is bounded by them is turned by 90 degrees and has a center at the origin.
Diagonal of this square would be 20, so the \(Area=\frac{20*20}{2}=200\). Or the \(Side= \sqrt{200}\), \(Area=\sqrt{200}^2=200\).
Re: Plz help to solve this ps [#permalink]
30 Apr 2010, 00:59
Bunuel wrote:
\(|\frac{x}{2}| + |\frac{y}{2}| = 5\)
After solving you'll get equation of four lines:
\(y<0\) and \(x<0\) --> \(y=-10-x\) \(y>0\) and \(x<0\) --> \(y=10+x\) \(y>0\) and \(x>0\) --> \(y=10-x\) \(y<0\) and \(x>0\) --> \(y=x-10\)
If you draw these four lines (line segments) you'll see that the figure (square) which is bounded by them is turned by 90 degrees and has a center at the origin.
Diagonal of this square would be 20, so the \(Area=\frac{20*20}{2}=200\). Or the \(Side= \sqrt{200}\), \(Area=\sqrt{200}^2=200\).
Hope it's clear.
I still dont understand how area becomes 200.. First, the question says certain region then how do you know its square or rectangle and not triangle.. Second, if each side of the length of square is 10 then area should be 100 no?
Please help me explain this..thanks
gmatclubot
Re: Plz help to solve this ps
[#permalink]
30 Apr 2010, 00:59
As I’m halfway through my second year now, graduation is now rapidly approaching. I’ve neglected this blog in the last year, mainly because I felt I didn’...
Perhaps known best for its men’s basketball team – winners of five national championships, including last year’s – Duke University is also home to an elite full-time MBA...
Hilary Term has only started and we can feel the heat already. The two weeks have been packed with activities and submissions, giving a peek into what will follow...