- #1
michonamona
- 122
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Hello everyone!
n!/(n-r)! = n(n-1)(n-2)...(n-r+1)
where r is the number of objects we want from n distinct objects (3 billiard balls out of 16)
I don't understand what the last term in the expansion means, the (n-r+1). For example, suppose we have 5 distinct objects and we want to choose 2. This means that n = 5 and r = 2
5x4x3x2x1x(5-2+1)
is this correct?
Thank you for your help
Homework Statement
n!/(n-r)! = n(n-1)(n-2)...(n-r+1)
where r is the number of objects we want from n distinct objects (3 billiard balls out of 16)
I don't understand what the last term in the expansion means, the (n-r+1). For example, suppose we have 5 distinct objects and we want to choose 2. This means that n = 5 and r = 2
5x4x3x2x1x(5-2+1)
is this correct?
Thank you for your help