Author Topic: S1 and S2 DOUBTS HERE!!!!  (Read 54239 times)

Freaked12

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Re: S1 DOUBTS HERE!!!!
« Reply #105 on: November 09, 2010, 11:33:08 pm »
Oh

This is already done
sorry

Offline Ivo

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Re: S1 DOUBTS HERE!!!!
« Reply #106 on: November 10, 2010, 08:02:59 pm »
A dice is known to be biased in such a way that, when it is thrown, the probability of a 6 showing is \frac{1}{4}.  This biased dice and an ordinary fair dice are thrown.  Find the probability that exactly one of the two dice shows a 6, given that at least one of them shows a 6.

Many thanks in advance; what does that last sentence even mean?!
« Last Edit: November 10, 2010, 08:26:19 pm by Ivo »
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Offline Arthur Bon Zavi

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Re: S1 DOUBTS HERE!!!!
« Reply #107 on: November 11, 2010, 05:03:55 am »
A dice is known to be biased in such a way that, when it is thrown, the probability of a 6 showing is \frac{1}{4}.  This biased dice and an ordinary fair dice are thrown.  Find the probability that exactly one of the two dice shows a 6, given that at least one of them shows a 6.

Many thanks in advance; what does that last sentence even mean?!

You have to find the probability that; if together both the dices are thrown, at-least from both, 1 shows a six, and from both 1 has to show 6.

1       1         5
-- + ---   = -----
4       6         12

Is this the answer ?

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Offline Deadly_king

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Re: S1 DOUBTS HERE!!!!
« Reply #108 on: November 11, 2010, 05:16:55 am »
You have to find the probability that; if together both the dices are thrown, at-least from both, 1 shows a six, and from both 1 has to show 6.

1       1         5
-- + ---   = -----
4       6         12

Is this the answer ?

Nope........you did it wrong there dude.

The question asked at least a six form both dices but exactly one six should be obtained.

Hence probable results are :
1. 6 from biased die and any other number from unbiased die.
2. Any other number from unbiased die and 6 from unbiased die.

Probability : (1/4 x 5/6) + (3/4 x 1/6) = 1/3

Offline Arthur Bon Zavi

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Re: S1 DOUBTS HERE!!!!
« Reply #109 on: November 11, 2010, 05:22:14 am »
Nope........you did it wrong there dude.

The question asked at least a six form both dices but exactly one six should be obtained.

Hence probable results are :
1. 6 from biased die and any other number from unbiased die.
2. Any other number from unbiased die and 6 from unbiased die.

Probability : (1/4 x 5/6) + (3/4 x 1/6) = 1/3

Yeah !! :D

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Offline Ivo

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Re: S1 DOUBTS HERE!!!!
« Reply #110 on: November 11, 2010, 08:03:07 pm »
Nope........you did it wrong there dude.

The question asked at least a six form both dices but exactly one six should be obtained.

Hence probable results are :
1. 6 from biased die and any other number from unbiased die.
2. Any other number from unbiased die and 6 from unbiased die.

Probability : (1/4 x 5/6) + (3/4 x 1/6) = 1/3

Hmm, apparently the answer is 8/9.  Any ideas?
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Offline astarmathsandphysics

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Re: S1 DOUBTS HERE!!!!
« Reply #111 on: November 11, 2010, 08:56:04 pm »
got 8/9. faffing around with scanner

Offline astarmathsandphysics

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Re: S1 DOUBTS HERE!!!!
« Reply #112 on: November 11, 2010, 09:05:48 pm »
here

Offline Arthur Bon Zavi

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Re: S1 DOUBTS HERE!!!!
« Reply #113 on: December 21, 2010, 02:30:45 pm »
Instinct change ! No doubts here now, for anybody. :o

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Offline vondutchLG

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Re: S1 DOUBTS HERE!!!!
« Reply #114 on: January 29, 2011, 10:06:29 am »
A:one of the two dice shows a 6
B:at least one of them shows a 6

first find B
a tree diagram would help...........
1/4*1/6+1/4*5/6+3/4*1/6=3/8
P(B)=3/8
P(A)=1/4*5/6+3/4*1/6=1/3
P(A!B)=this means probabiltiy of A given that B
P(A)=1/3 / 3/8=8/9

hop u get it

Offline ashish

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Re: S1 DOUBTS HERE!!!!
« Reply #115 on: February 10, 2011, 03:22:36 am »
there are 6 boys and 3 women ..

how many possible ways are there if no 2 women are standing next to each other?
ans : 151200
« Last Edit: February 10, 2011, 05:08:21 am by ashish »

Offline astarmathsandphysics

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Re: S1 DOUBTS HERE!!!!
« Reply #116 on: February 10, 2011, 01:40:34 pm »
here

Offline ashish

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Re: S1 DOUBTS HERE!!!!
« Reply #117 on: February 11, 2011, 04:43:41 am »

Saavya

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Re: S1 DOUBTS HERE!!!!
« Reply #118 on: February 15, 2011, 05:58:22 pm »
Hello  :) im taking cie s1 and wondering if u know the way to find standard deviation on calculator , i use casio fx-991es and cant find any help on web  :-\

Offline EMO123

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Re: S1 DOUBTS HERE!!!!
« Reply #119 on: February 16, 2011, 07:55:36 am »
A coin is tossed 10 times
(a) How many different sequences of heads and tails are possible.
(b) How many different sequences containing six heads and four tails are possibles.
(c) What is the probability of getting six heads and four tails.