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

 It is currently 25 Apr 2015, 22:23

### 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

# 1)60% people have diabetes, and 56% have insomnia. None have

Author Message
TAGS:
Director
Joined: 01 Jan 2008
Posts: 513
Followers: 3

Kudos [?]: 47 [0], given: 0

1)60% people have diabetes, and 56% have insomnia. None have [#permalink]  22 Apr 2008, 22:35
1)60% people have diabetes, and 56% have insomnia. None have neither. What is the probabaility that a person with insomnia has no diabetes.

2) A has 4 prime factors. B has 3 prime factors. 15 is a common factor to A and B . How many prime factors does AB have.

3) An ellipse is inscribed in a rectangle . The area of an ellipse is given by 1/2 * pi* a * b , where a is the length of the minor axis , and b the major axis. What is the area of the ellipse .

1) Length of the rectangle is 12

2) Breadth of the rectangle is 24.
Senior Manager
Joined: 29 Jan 2007
Posts: 450
Location: Earth
Followers: 2

Kudos [?]: 40 [0], given: 0

Re: Math Questions [#permalink]  22 Apr 2008, 22:46
1) 40/56?

56+60-100 = inso + diab
therfore 40 only inso , 44 only diab

Senior Manager
Joined: 19 Apr 2008
Posts: 325
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 00:02
I think it should be 40/100 (inso/total) , so prob . is 2/5 ?
Senior Manager
Joined: 19 Apr 2008
Posts: 325
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 00:10
2) A has 4 prime factors. B has 3 prime factors. 15 is a common factor to A and B . How many prime factors does AB have.

Answer to this is 5 ? 2 common factors + 2 ( remaining prime factor for A) +1 (remaining prime factor for B)

3) An ellipse is inscribed in a rectangle . The area of an ellipse is given by 1/2 * pi* a * b , where a is the length of the minor axis , and b the major axis. What is the area of the ellipse .

I would go with E , since it is not given whether sides of rectangles are tangent to ellipse or not . What is OA?
Senior Manager
Joined: 29 Jan 2007
Posts: 450
Location: Earth
Followers: 2

Kudos [?]: 40 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 08:39
rpmodi wrote:
I think it should be 40/100 (inso/total) , so prob . is 2/5 ?

I think my answer is correct on this one.

Here is similar example. If you have even number after rolling dice, what is probability it is 2.

Answer here is 1/3 not 1/6

Let me know if you think I am not reading question correctly.
Senior Manager
Joined: 29 Jan 2007
Posts: 450
Location: Earth
Followers: 2

Kudos [?]: 40 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 08:43
Ans 2 - 5 (A has factors 3,5,x,y, B has factors 3,5,z so AB has 3,5,x,y,z)
Ans 3 - Not sure...but could be C. Inscribed means it is touching all sides of rectangle.

Anyone else on this Q 3.
Senior Manager
Joined: 19 Apr 2008
Posts: 325
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 13:01
Yes you are right , inscribed means its tangent , I might be dreaming while woring on this one !
VP
Joined: 10 Jun 2007
Posts: 1465
Followers: 6

Kudos [?]: 133 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 19:39
bhatiagp wrote:
1)60% people have diabetes, and 56% have insomnia. None have neither. What is the probabaility that a person with insomnia has no diabetes.

2) A has 4 prime factors. B has 3 prime factors. 15 is a common factor to A and B . How many prime factors does AB have.

3) An ellipse is inscribed in a rectangle . The area of an ellipse is given by 1/2 * pi* a * b , where a is the length of the minor axis , and b the major axis. What is the area of the ellipse .

1) Length of the rectangle is 12

2) Breadth of the rectangle is 24.

1) Set x = both diabetes and insomnia
60-x + x + 56-x = 100
x= 16
Therefore, ONLY insomnia is: 56 - 16 = 40
P(only insomnia) = 40/100 = 2/5

2) I don't quite get the question, AB can have 5 primes or 4 primes
Director
Joined: 01 Jan 2008
Posts: 513
Followers: 3

Kudos [?]: 47 [0], given: 0

Re: Math Questions [#permalink]  23 Apr 2008, 22:04
1 ) 2/5

2) 5 factors

3) Need your opinion. Similiar question appeared for a friend, and Im not sure whether inscribed means rectangle sides are tangential to ellipse

Last edited by bhatiagp on 01 Jul 2008, 21:59, edited 1 time in total.
SVP
Joined: 29 Aug 2007
Posts: 2497
Followers: 57

Kudos [?]: 554 [0], given: 19

Re: Math Questions [#permalink]  23 Apr 2008, 22:13
bhatiagp wrote:
1 ) This is a question of conditional probability .

Probability that a person has insomina but no diabetes = 1 - ( Prob of Insomina and diabetes)
= 1- ( 16/56 ) = ( 40/56) = 5/7

you are finding a prob that a person has insomina but no diabetes. so take a person (with insomina but no diabetes) out of total.

so it should be 40/100 = 2/5 not 5/7.
_________________
Senior Manager
Joined: 19 Apr 2008
Posts: 325
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: Math Questions [#permalink]  25 Apr 2008, 13:40
bhatiagp wrote:
1 ) This is a question of conditional probability .

Probability that a person has insomina but no diabetes = 1 - ( Prob of Insomina and diabetes)
= 1- ( 16/56 ) = ( 40/56) = 5/7

2) 5 factors

3) Need your opinion. Similiar question appeared for a friend, and Im not sure whether inscribed means rectangle sides are tangential to ellipse

Intern
Joined: 28 Mar 2008
Posts: 35
Followers: 0

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

Re: Math Questions [#permalink]  25 Apr 2008, 14:35
Q2 it is 5 factors
Is the answer for Q3 is 144*pi
Re: Math Questions   [#permalink] 25 Apr 2008, 14:35
Similar topics Replies Last post
Similar
Topics:
As of this morning, none of my friends have been able to 30 20 Jul 2011, 10:47
2 As of this morning, none of my friends have been able to 10 28 Mar 2011, 00:10
None of my friends have been OR None of my friends has been 7 13 Mar 2008, 21:02
As of this morning, none of my friends have been able to 7 26 Jun 2006, 08:00
As of this morning, none of my friends have been able to 15 18 Apr 2006, 22:18
Display posts from previous: Sort by