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#76 2006-04-23 04:51:57

krassi_holmz
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Registered: 2005-12-02
Posts: 1,908

Re: *** Problems

27.


IPBLE:  Increasing Performance By Lowering Expectations.

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#77 2006-04-23 04:55:21

krassi_holmz
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Registered: 2005-12-02
Posts: 1,908

Re: *** Problems

28.


IPBLE:  Increasing Performance By Lowering Expectations.

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#78 2006-04-23 16:09:19

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

Excellent, krassi_holmz! Keep up the good work!


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#79 2006-04-24 17:07:06

ganesh
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Registered: 2005-06-28
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Re: *** Problems

***29. Out of 40 students, 25 are boys, 16 are married, 10 are married boys. What is the probability that a chosen student would be an unmarried girl?


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#80 2006-05-02 03:06:04

ganesh
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Re: *** Problems

***30. If x,y, and z be respectively the sums of p, q, and r terms of an Arithmetic Progression, prove that


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#81 2006-06-07 02:26:04

ganesh
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Re: *** Problems

***31. Two numbers are selected at random from 1,2,3,4,....100 and are multiplied. Find the probability of the product being a multiple of 3.

***32. A and B are two independent events. The probability that both A and B occur is 1/6 and that of neither of them occuring is 1/3. Find the probability of occurence of A.


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#82 2006-06-12 00:34:34

Ninja 101
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Registered: 2006-02-20
Posts: 936

Re: *** Problems

Annoyed statement:
I can never read that writing like in ***30
and what's more I told you.


Chaos is found in greatest abundance wherever order is being saught. It always defeats order, because it is better organized.

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#83 2007-03-24 10:07:13

lightning
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Registered: 2007-02-26
Posts: 2,061

Re: *** Problems

they are 10 boy marred too each other?


Zappzter - New IM app! Unsure of which room to join? "ZNU" is made to help new users. c:

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#84 2007-03-24 10:28:18

Devantè
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Registered: 2006-07-14
Posts: 6,400

Re: *** Problems

Firstly, don't post in a 9-month-old thread unless you have something to contribute...I think even you know that 10 boys are not married to each other.

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#85 2007-03-24 10:31:31

lightning
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Registered: 2007-02-26
Posts: 2,061

Re: *** Problems

this is 9 months old? i no that but it's a puzzle it's sopost to be tricky!


Zappzter - New IM app! Unsure of which room to join? "ZNU" is made to help new users. c:

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#86 2007-04-24 05:09:28

Eeyore
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Registered: 2007-04-16
Posts: 8

Re: *** Problems

ganesh wrote:

***32. A and B are two independent events. The probability that both A and B occur is 1/6 and that of neither of them occuring is 1/3. Find the probability of occurence of A.

Sorry, not enough information to find a unique solution.

I found that P(A) is not equal to P(B).  And, since A and B are interchanged "without loss of generality," a.k.a. WOLOG,
then it seems there are two possibilities for P(A).

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#87 2007-04-27 05:37:33

Stanley_Marsh
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Registered: 2006-12-13
Posts: 345

Re: *** Problems

To 31
  there are 33 numbers which are the multiple of 3 , then the probability of chosing one from 1-100 will be 33/100  , if u chose two number which are not the multiple of 3 , then the probability is (67/100)^2 , then the probability we want is  1- (67/100)^2

To 32 ,
  P(A)=x , P(B)=y
xy= 1/6 ,  (1-x)(1-y)=1/3
y=5/7 ,x= 7/30

Last edited by Stanley_Marsh (2007-04-27 05:42:58)


Numbers are the essence of the Universe

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#88 2007-04-27 07:18:22

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

Re: *** Problems

Or perhaps x=5/7, y=7/30. We don't know, and that's the point Eeyore was making.
Wologs are cute.


Why did the vector cross the road?
It wanted to be normal.

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#89 2007-04-27 10:35:40

Stanley_Marsh
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Registered: 2006-12-13
Posts: 345

Re: *** Problems

I check that
P(A on , B off) + P(B on , A off ) + P(A on ,B on ) +P(A off ,B off ) =1


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#90 2007-09-30 01:32:54

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

***33. A Pythagorean triple is a set of three numbers such that the sum of squares of the first two numbers is equal to the square of the third. For example, (3,4,5) is a Pythagorean triple. These formthe lengths of the three sides of a right angled triangle.

Prove that there are an infinite number of primitve Pythagorean triples ( The set (6,8,10) is a Pythagorean triple but not a primitve Pythagorean triple because it is of the form(3n,4n,5n) where n=2 and (3,4,5) is a Pythagorean triple. For example,another primitve Pythagorean triple is(5,12,13)).


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#91 2007-10-01 19:16:49

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

***34. Prove that a rhombus is a cyclic quadrilateral if and only if it is a square.

***35. Prove that a parallelogram is a cyclic quadrilateral if and only if it is rectangle.


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#92 2007-10-14 02:05:33

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

***36. In a get-together, every person present shakes hand with every other person once. If there are 91 handshakes in all, how many persons attended the party?


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#93 2007-10-14 11:45:25

pi man
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Registered: 2006-07-06
Posts: 251

Re: *** Problems

Last edited by pi man (2007-10-14 11:47:56)

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#94 2007-10-14 13:19:52

JaneFairfax
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Registered: 2007-02-23
Posts: 6,868

Re: *** Problems


Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?

A: Click here for answer.

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#95 2007-10-15 00:08:45

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

Outstanding, pi man and Jane Fairfax!!!
wave


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#96 2007-10-19 02:24:03

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

37. A vendor has a pair of weighing scales and four weights, the total of all the four weights being 40 kilograms. With the help of any or multiple of these four weights alone and only one wighing on the scale, he can weigh any integral value of weight from 1 to 40 kilograms, both inclusive. How many do these four weights measure?


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#97 2007-10-30 03:33:41

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

38. Can you give a list of 1,000 consecutive non-primes?


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#98 2007-10-31 03:22:47

ganesh
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Registered: 2005-06-28
Posts: 15,149

Re: *** Problems

39. How many prime numbers approximately lie between 1 and 1000?

40. What do 1296 and 625 have in common?


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#99 2007-10-31 03:31:58

JaneFairfax
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Registered: 2007-02-23
Posts: 6,868

Re: *** Problems


Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?

A: Click here for answer.

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#100 2007-10-31 04:12:31

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

Re: *** Problems


Why did the vector cross the road?
It wanted to be normal.

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