posted by Kelsey on .
I need help with these probability problems.
1). Five chips are selected from a bag without replacement. The bag originally contained 6 yellow chips and 8 red chips. In how many ways can you choose 5 chips from the bag?
I did 14 C 5 and got 2002, is that correct.
2). In how many ways can you choose no yellow chips?
you have to look at the results,
you have 5 chips selected, that could be one of the following cases :
0Y 5R .... RRRRR, only 1 way OR 5!/0!5!)
1Y 4R .... YRRRR, OR RYRRR, ... 5!/4! = 5
2Y 3R .... 5!/(2!3!) = 10
3Y 2R .... 5!/(3!2!) = 10
4Y 1R .... 5!/(4!1!) = 5
5Y OR .... 5!/(5!0!) = 1
total number of ways is 32
This is not a probability question, but rather based on the little formula
for the number of ways that you can arrange p things, q alike of one kind, and r alike of another kind, which is
2) the number of ways you can choose no yellow chips is 1, namely RRRRR
Had you asked "what is the probability of choosing no yellow chip in choosing any 5 chips from the above that would be
1/( 14C5 ) = 1/2002
I said at the end
"Had you asked "what is the probability of choosing no yellow chip in choosing any 5 chips from the above that would be
1/( 14C5 ) = 1/2002 "
that should have been 1/32