A committee of 5 people is randomly selected from 6 married couples (12 people). What is the probability that a husband and wife do not belong to that committee?What is the probability that a husband and wife do not belong to that committee?
Total combinations = 12C5
Favourable cases-
Ways to select first member = 12
second member no. of ways = 10 (excluding the spouse of first one)
third = 8 (excluding spouses of first 2)
fourth = 6 (excluding spouses of first 3)
fifth = 4 (excluding spouses of all 4)
Multiply and get the possibile conditions = 12*10*8*6*4
Probability =
12C5 / 12*10*8*6*4
(8*9*10*11*12/2*3*4*5) / 12*10*8*6*4
= 6*11*12 / 12*10*8*6*4
= 11 / 10*4*8
= 11 / 320
Hope this helps !What is the probability that a husband and wife do not belong to that committee?
1 - P(Both Belong To Committee) =
1 - [(10 Ncr 3) / (12 Ncr 5)] =
1 - [120 / 792] =
1 - .151515... =
.848484... =
28/33
You must choose one or none from each couple, so it's 2* 6C5
2( 6C5 )=2(1/6)=1/3
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