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Total committees:

Choose 3 people from 8 = 56

Invalid committees:

Aly & Ben together: 6

Cam & Dan together: 6

No overlap (a 3-person committee can't contain both pairs).

Total invalid:
6+6=12

Valid committees:
56−12=44

Probability:

44 over 56 = 11/14


Answer: X = 11, Y = 14.
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For this problem, we are trying the find the fraction of valid combinations of committees. First I started be calculating the denominator. For that we need the total number of possible committees. Since order does not matter, we will use the combinations formula: n!/((n-4)!r!). n = 8 because we have 8 potential committee members and r = 3 since a committee is 3 members. So, 8!/(5!3!).

8! = 8*7*6*5*4*3*2*1
5! = 5*4*3*2*1
3! = 3*2*1

We can simplify the formula by canceling out 5! from the top and the bottom (Notice that 8! = 8*7*6*5!) which leaves us with (8*7*6)/(3*2*1) = 56.

To get the numerator, we must find the number of valid committees. Well the number of valid committees is equal to total minus invalid committees. We know Aly and Ben cannot be together so we need to take out the combinations with them both in it. Since there are only 3 spots in a committee and they would take up two, the number of invalid combinations including them would equal the number of remaining potential committee members which is six. The same logic goes for committees with Cam and Dan so that is six more invalid committees which gives us a total of 12. 56-12 is 44 valid commitees so the answer is 44/56 which simplifies down to 11/14
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I solved it in this way:
There are a total of 56 ways to pick 3 people: 8C3 = 56 (We use the Combinations formula because order does not matter)
We first need to find the probability of picking a 'wrong' committee. That means picking AB or CD in one committee.
If AB is in one committee, that means anyone from the remaining 6 people can be there, which means 6 'wrong' committees.
Similarly, if DC is in one committee, there are also 6 'wrong' ones.
56 - (6+6) = 44
44/56 = 11/13
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There are 8C3 way to form a team of 3 out of 8 people => 56 ways

Then we will find how many ways to form a team with A-B => there are only 1 slots left for 6 people => 6 ways, C and D are the same so 12 ways.

=> To form a team without A-B and C-D 1- 12/56 = 11/14
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The total number of pairs possible is 8C3, which is 56.

Let's use the complementary method by subtracting the cases not allowed from the total.

Total number of invalid cases will be when we have [A,B] on a team and [C,D] on a team. For each of these, there are 6 possible teams which can be selected (6 remaining from the total of 8).
Therefore, the total number of not allowed cases will be 6 + 6 = 12.

56 - 12 = 44.

44 (total number of allowed cases) / 56 (total number possible cases) simplifies to 11/14.
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Both X and Y committee are valid with these selected candidates
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We must exclude one member from each uncompatible group - so we have only 6 one left .
There are 20 ways to select 3 member from 6 member .


if we now exclude previous two problematic member and add their opposite ones , we still have 6 members , and just like before there are 20 ways to select 3 members from 6 people as 6! / 3! 3! is 20 .

if we consider only 4 non problematic members there are 4 ways to select 3 members from them .

So total ways to select a committee of 3 member is 4+20+20=44
Total ways to select 3 members from 8 people is 56 . so , x/ y is 44/ 56 or 11/ 14
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Total count will be 8!/3!*5!= 56

now count when Aly and Ben are together using slot method 3*2*1=6
cam and den together = 3*2*1= 6

not together = 56-6-6= 44
probability = 44/56= 11/14
X=11 and Y = 14
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i am going with the option 11 as x and 14 as y.
we are given 8 people and have to form committee of 3 people that is 8!/3!5! = 8x7x6x5!/3x2x1x5! = 56
we are given that two combo cannot be together and makes the team invalid so if we take first combo of a and b and to make a 3 people team we have 6 people to choose from making 6 teams invalid. same goes with the second combo of c and d giving us another 6 invalid teams. therefore we have total 12 invalid teams. 56-12 = 44. now we have 44 valid combos to choose from 56 making it 44/56 = 11/14.
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A,B,C,D,E,F,G,H

select 3 people.

now A and B cant be together in committee.
C and D cant be together.

valid committee- 3 members do not include either of these pairs.

select 3 people from 8 first. 8C3 = 56

now rather getting into complex scenario, just go the opposite way, form invalid committee and subtract from total num.

so invalid consist of AB and any person from rest. or CD and any person from rest.

so if AB are selected then we have 6 people to choose from for last seat.
similarly if CD are selected then we again have 6 people.

so total 12 invalid committee.

56-12 = 44

44/56
11/14

x= 11
y =14
Bunuel
A company is forming a three-person leadership committee from a pool of eight qualified candidates: Aly, Ben, Cam, Dan, Emi, Fay, Gia, and Hal. Due to conflicts of interest, two pairs of candidates are incompatible: Aly and Ben cannot both serve on the committee together, and Cam and Dan cannot both serve on the committee together. A committee is considered valid only if its three members do not include either of these pairs of incompatible candidates.

Consider the following incomplete sentence:

If three candidates are chosen at random, the probability that the selected candidates form a valid committee is X / Y , where the fraction is expressed in simplest form.

Select for X and Y values that are consistent with the information provided. Make only two selections, one in each column.
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so ,, 3 people from a , b, c , d , e , f , g ,h so 3 out of 8 people and conditions are ( a, b ) and (c ,d ) not together
--- so _ _ _ here 3 space and it will be easy if we Do the opposite not possible to create a valid committee so on three __ __ __ took a b then and then 6 digits left so it is 6 and then another set c d then same way 6 digits left so in total it is 12 ways that we cant create .
-- now total creation with no limitation is 8 C 3 ways so 8 ! / 3 ! so the number of ways 56
-- now x / y = 56 - 12 / 56 = 11 / 14 so here x / y so here is x = 11 and y = 14
It's the way I did if anybody has a better approach feel free to tag or share !!
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x=11
y=14


Total outcomes= 8c3= 56
Outcomes not favourable= aly x ben x 6c1 + cam x dan x 6c1= 6+6=12

Favorable outcomes= 56-12= 44
44/56= 11/14
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The answer to the question is: X=11 and Y= 14.

Let's calculate the total outcomes:
8C3= 8!/5!*3! = 56 outcomes.

For invalid outcomes, i.e the possibilities when Aley and Ben are selected together, or Cam and Dan are selected together.
For each situation, 2 members are already selected, and thus for the 3rd person the possibility would be 6C1= 6
6*2= 12 invalid outcomes.

Hence, the total valid outcomes would be 56-12= 44.

Possibility= Valid outcomes/ Total = 44/56= 11/14.

X=11
Y=14.
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So, I used the approach of finding the probability where teams can be formed using these conflicted pair:
Probability of a team forming from the pair of Aly and Ben OR from the pair of Cam and Dan is:

= \((1/8 * 1/7 * 6/6) * 2 + (1/8 * 1/7 * 6/6) * 2 = 4/56 = 1/14\)

So, probability that the teams formed do not include these pairs = \(1 - 1/14 = 13/14\)

X = 13, Y = 14; IMO.
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So here is my thought process —>
Total possible outcomes = 8C3 =8!/3!5! =56
Total Valid outcomes = Total - Invalid outcomes
Invalid outcomes = Aly, Ben and third person being any one from Cam to Hal = 6 Pairs
Similarly Cam, Dan and any one person from the remaining pool of 6 people = 6 Pairs
Therefore, total invalid pairs = 12
Total valid pairs = 56-12 =44
Probability of valid pair = Total valid outcome / Total outcomes = 44/56
44/56 in it’s simplest form is 22/28 = 11/14
Therefore X= 11 and Y = 14
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Answer: 11/14

Number of desirable/valid outcomes = total possible outcomes - outcomes including AB - outcomes including CD
Outcomes including AB = ABC, ABD, ABE.... = 6
Number of possible outcomes = 8C3 = 56

Probability that the selected candidates form a valid committee = (56 - 6 - 6)/56 = 44/56 = 11/14
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This correct answer is 11/14
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