nCk= The combinations of n taken k at a time.
which of the following is equal to 11C8?
a) 11!/3!
b) 11!/11!8!
c) 11!/8!3!
d) 11!/8!

Question

anonymous · Answer

Is it a..?

anonymous · Answer

no c

anonymous · Answer

nCr = n!/r!(n-r)!

anonymous · Answer

c is the right choice

anonymous · Answer

nPk = n!/(n-k)1

anonymous · Answer

right

anonymous · Answer

dont be confused between permutations and combination , both are different

anonymous · Answer

yep agreed :D

anonymous · Answer

I'm confused between the two formulas and two answers

anonymous · Answer

11C8= 11!
            -----
            8!*3!

anonymous · Answer

i have a way
combination : we only select the items
permutation: we select and we also arrange the items

anonymous · Answer

umm .. sorry that will be when u do problems of probability

anonymous · Answer

but metarock ur definition is right

anonymous · Answer

ya but chizzle was confused in the formulas , a different context though

anonymous · Answer

Ah, just found a way to remember (P)ermutation ... (P)osition matters both begin with P

anonymous · Answer

(C)ombination and (C)ounting (or selecting) 

;-)

anonymous · Answer

So then it is 11!/8!3! ?

anonymous · Answer

yups

anonymous · Answer

Okay thank you all for the help/formulas/and differences between them

anonymous · Answer

ur welcome