General COMBINATON doiubt

[saxenankit]

Dear experts ,

please have a look at the below question -

Kurt, a painter, has 9 jars of paint: 4 are Yellow, 2 are Red and 3 are brown. Kurt will combine 3 jars of paint into a new container to create a new shade. IN how many ways can he do this ?

Source : I have created this sample problem to clear my doubt

My doubt : Can I say 9C3, --
If yes, then won't 9C3 would give a wrong result since the collection has 4 same types of Yellow paint, 2 same type of red and 3 of brown.
If no, then what should be the approach to solve it.

Thanks,
Ankit Saxena

[callmepret]

Answer:

three ways of doing this:

1. all paints same color = 3 ways
2. 1 paint different = 3 c2 = 3
3. all different = 1


7 ways

[tim]

this question is not sufficiently well-defined to have an answer. does it matter which of the four yellow jars we choose? if not, why make it clear that there are four of them rather than a million? if so, why have any of them be the same color? give us a question that can be answered, and we'll be happy to answer it.. :)