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# Time yourself 2. Work this problem on paper as fast as you

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CEO
Joined: 15 Aug 2003
Posts: 3467
Followers: 61

Kudos [?]: 718 [0], given: 781

Time yourself 2. Work this problem on paper as fast as you [#permalink]  07 Mar 2004, 22:56
1. Time yourself
2. Work this problem on paper as fast as you can ( doing this under 2 mins is our goal)

Go!

Two events A & B are such that P(A) = 0.83, P(B) = 0.25. If C is a set of possible values of probability that A & B both occur, Find the range of C?
Intern
Joined: 12 Jan 2004
Posts: 26
Location: Israel
Followers: 0

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

Am I missing something or is the answer X*Y = 0.2075 (30sec.)?
Director
Joined: 03 Jul 2003
Posts: 654
Followers: 2

Kudos [?]: 32 [0], given: 0

P(C) = 0.2075
(Time less than a minute)
Senior Manager
Joined: 23 Sep 2003
Posts: 294
Location: US
Followers: 1

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

That's a bad question. I don't see how there could be a range. There's only one possible answer and that is 0.207 which is not a range.
SVP
Joined: 30 Oct 2003
Posts: 1794
Location: NewJersey USA
Followers: 5

Kudos [?]: 43 [0], given: 0

If these two events are mutually exclusive then P(A&B) = 0
if these are independent events and not mutually exclusive
P(A&B) = P(A) & P(B) = 0.2075

If they are dependent events
P(A or B) = P(A) + P(B) - P(A&B)
Max of P(A OR B) = 1
P(A&B) = 0.83+0.25 - 1 = 0.08

Range is 0.08 to 0.2075
or the range is
0 to 0.2075
CEO
Joined: 15 Aug 2003
Posts: 3467
Followers: 61

Kudos [?]: 718 [0], given: 781

ndidi204 wrote:
That's a bad question. I don't see how there could be a range. There's only one possible answer and that is 0.207 which is not a range.

nope, i hope to prove that none of you is right.

Range = Maximum - Minimum
1. what is the Maximum possible value of C?
2. what is the Minimum possible value of C?
SVP
Joined: 30 Oct 2003
Posts: 1794
Location: NewJersey USA
Followers: 5

Kudos [?]: 43 [0], given: 0

Hi Praetorian,

Would you mind explaining the solution. Already enough people have pounded on this.

Anand.
CEO
Joined: 15 Aug 2003
Posts: 3467
Followers: 61

Kudos [?]: 718 [0], given: 781

anandnk wrote:
Hi Praetorian,

Would you mind explaining the solution. Already enough people have pounded on this.

Anand.

Sure.

1. The events A and B cannot be mutually exclusive.
P(A) + P(B) > 1
so, the minimum value of C cannot be 0.
the minimum C is 0.83 + 0.25 - 1 = 0.08

2. About the maximum, that will occur when B is a subset of A.
that is C = 0.25

you answer then is Range = 0.25 -0.08 =0.17

questions?
SVP
Joined: 30 Oct 2003
Posts: 1794
Location: NewJersey USA
Followers: 5

Kudos [?]: 43 [0], given: 0

Hmm,

I was atleast half right. Never thought of this scenario where B could be part of A.

Thanks,
Anand.
CEO
Joined: 15 Aug 2003
Posts: 3467
Followers: 61

Kudos [?]: 718 [0], given: 781

anandnk wrote:
Hmm,

I was atleast half right. Never thought of this scenario where B could be part of A.

Thanks,
Anand.

I will give y'all answer choices next time.
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