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.

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:

In the xy-plane, the vertex of a square are (1, 1), (1,-1), [#permalink]
21 Dec 2009, 02:33

00:00

A

B

C

D

E

Difficulty:

35% (medium)

Question Stats:

66% (02:27) correct
34% (00:57) wrong based on 37 sessions

In the xy-plane, the vertex of a square are (1, 1), (1,-1), (-1, -1), and (-1,1). If a point falls into the square region, what is the probability that the ordinates of the point (x,y) satisfy that x^2+y^2>1?

In the xy-plane, the vertex of a square are (1, 1), (1,-1), (-1, -1), and (-1,1). If a point falls into the square region, what is the probability that the ordinates of the point (x,y) satisfy that x^2+y^2>1? (A) 1-pi/4 (B) pi/2 (C) 4-pi (D) 2-pi (E) Pi-2

kindly help me to understand the q and provide a simple , step by step digesteble solution

x^2 + y^2 = R^2 is the equation of a circle with centre (0,0) and radius R

If we draw the square and the circle, then we will see that the circle is inscribed in the square i.e. the diameter of the circle is equal to the length of the side of square.

Area of the circle= pi (1)^2=pi Area of the square=(2)^2 = 4

The proabibility that the point lies within the square and outside the circle is

(Area of the sqaure - area of the circle)/area of the circle = 4-pi/4 =1 - pi/4

In the xy-plane, the vertex of a square are (1, 1), (1,-1), [#permalink]
21 Dec 2009, 03:40

1

This post received KUDOS

Expert's post

2

This post was BOOKMARKED

delta09 wrote:

In the xy-plane, the vertex of a square are (1, 1), (1,-1), (-1, -1), and (-1,1). If a point falls into the square region, what is the probability that the ordinates of the point (x,y) satisfy that x^2+y^2>1? (A) 1-pi/4 (B) pi/2 (C) 4-pi (D) 2-pi (E) Pi-2

kindly help me to understand the q and provide a simple , step by step digesteble solution

First note that the square we have is centered at the origin, has the length of the sides equal to 2 and the area equal to 4.

x^2+y^2=1 is an equation of a circle also centered at the origin, with radius 1 and the area=\pi{r^2}=\pi.

We are told that the point is IN the square and want to calculate the probability that it's outside the circle (x^+y^2>1 means that the point is outside the given circle):

Attachment:

Untitled.png [ 9.91 KiB | Viewed 119 times ]

P=Favorable outcome/Total number of possible outcomes.

Favorable outcome is the area between the circle and the square=4-\pi Total number of possible outcomes is the area of the square (as given that the point is in the square) =4

hi .. i think ans will be D... 2 is the diag and not side and each side is 2^(1/2)... area is 2...

Not so.

In our case we have "horizontal" square: side=2, area=4.

We would have the square with diagonal 2 if the vertices were: (0,1), (1,0), (0,-1), (-1,0). In this case if the point is IN the square it can not be outside the circle, as the square, in this case, is inscribed in the circle. Hence the probability would be 0. _________________

Re: In the xy-plane, the vertex of a square are (1, 1), (1,-1), [#permalink]
05 Oct 2014, 20:06

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Hey everyone, today’s post focuses on the interview process. As I get ready for interviews at Kellogg and Tuck (and TheEngineerMBA ramps up for his HBS... ...

I got invited to interview at Sloan! The date is October 31st. So, with my Kellogg interview scheduled for this Wednesday morning, and my MIT Sloan interview scheduled...