Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 27 May 2015, 12:14

### GMAT Club Daily Prep

#### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Set T consists of all points (x, y) such that x^2 + y^2 =1.

Author Message
TAGS:
Manager
Joined: 14 May 2005
Posts: 85
Location: San Francisco
Followers: 1

Kudos [?]: 2 [0], given: 0

Set T consists of all points (x, y) such that x^2 + y^2 =1. [#permalink]  14 Oct 2006, 13:50
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Set T consists of all points (x, y) such that x^2 + y^2 =1. If point (a, b) is selected from set T at random, what is the probability that b > a + 1?

(A) 1/4
(B) 1/3
(C) 1/2
(D) 3/5
(E) 2/3
SVP
Joined: 01 May 2006
Posts: 1804
Followers: 8

Kudos [?]: 101 [0], given: 0

For me (A),

In an XY plan, x^2+y^2 = 1 represents a circle with a radius of 1 and the center 0(0,0).

The area of circle that is matching the inequality b > a+1 is in the cadran II. It's 1/4 of the circle (not completly actually but anyway).

Thus, the probability to select 1 point on this arc is 1/4.
Manager
Joined: 14 May 2005
Posts: 85
Location: San Francisco
Followers: 1

Kudos [?]: 2 [0], given: 0

Fig, thanks.

I think that the wordings of the question are wrong. The question must be that what is the probability that b >= a + b. Otherwise, the probability must be slightly less than Â¼, since the two boundary points (0, 1) & (-1, 0) cannot be part of the selection. This question is from one of the Challenges.
Similar topics Replies Last post
Similar
Topics:
9 Set T consists of all points (x,y) such that x^2+y^2 =1 14 28 Nov 2010, 07:54
Set T consists of all points (x, y) such that x^2 + y^2 = 1. 6 26 Aug 2008, 11:26
Let *x* = x^2-1 and $y$ = 6y^2 - (*y*) for all integers x 3 15 May 2008, 11:49
Set T consists of all points (x,y) such that x^2 + y^2 = 1. 6 19 Nov 2007, 06:50
Distance between points A (x1,Y1)and B(x2,y2): AB2 = (y2 2 16 Jan 2006, 09:09
Display posts from previous: Sort by