# permutation and combination

• Feb 4th 2009, 01:35 PM
nikk
permutation and combination
Calculate number of ways
(a) 5 children can be divided into group of 2 and 3,(ans: 10)
(b) 9 children can be divided into group of 5 and 4,(ans: 126)
Hence calculate number of ways in which 9 children can be divided into groups of 2,3 and 4.(ans: 1260)

thank for tour time and help
• Feb 4th 2009, 01:41 PM
Plato
Quote:

Originally Posted by nikk
Calculate number of ways
(a) 5 children can be divided into group of 2 and 3,(ans: 10)
(b) 9 children can be divided into group of 5 and 4,(ans: 126)
Hence calculate number of ways in which 9 children can be divided into groups of 2,3 and 4.(ans: 1260)

You have the answers, so what is the question?
Do you want to know how?
$\frac{9!}{(2!)(3!)(4!)}=1260$
• Feb 4th 2009, 04:14 PM
nikk
Quote:

Originally Posted by Plato
You have the answers, so what is the question?
Do you want to know how?
$\frac{9!}{(2!)(3!)(4!)}=1260$

i don't no how to calculate it sir.tq for your step. how abour a&b
• Feb 4th 2009, 04:21 PM
Plato
Quote:

Originally Posted by nikk
i don't no how to calculate it sir.tq for your step. how abour a&b

If that is true then why are you asked to do these problems?