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nikhilgmat31
- Legendary Member
- Posts: 518
- Joined: Tue May 12, 2015 8:25 pm
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Please suggest when to use nCr formula to select a item for a group.
lets says we need to select 1 blue ball from 5 blue,4 Green & 3 Yellow Balls. - then we can simple take 5/12
Then What is the need of writing 5C1/12 - however 5C1 also gives 5
In other case
lets says we need to select 2 blue ball from 5 blue,4 Green & 3 Yellow Balls. - then we can simple take 5/12 * 4/11 = 5/33
In that case do we need to write it as 5C2 = 10
What will be denominator in this case-- is it 12
so probability is 5C2/12 = 10/12 = 5/6
Please suggest . I am confused.
lets says we need to select 1 blue ball from 5 blue,4 Green & 3 Yellow Balls. - then we can simple take 5/12
Then What is the need of writing 5C1/12 - however 5C1 also gives 5
In other case
lets says we need to select 2 blue ball from 5 blue,4 Green & 3 Yellow Balls. - then we can simple take 5/12 * 4/11 = 5/33
In that case do we need to write it as 5C2 = 10
What will be denominator in this case-- is it 12
so probability is 5C2/12 = 10/12 = 5/6
Please suggest . I am confused.
