Question

a jar contains 7 blue and 6 red. in how many ways can 2 red and 2 blue be chosen?

Answer 1

familiar with combination formula?

Answer 2

yes, c(n,n) ?

Answer 3

you meant C(n,r) ?

Answer 4

yes, sorry!

Answer 5

So there are 7 blue (balls?) and you choose 2. Wouldn't it be C(7,2) ? Same thing for the red ones. C(6,2). By the Counting principle, the total combination is C(7,2) x C(6,2)

Answer 6

would that be 21x15?

Answer 7

yea

Answer 8

Thank you so much!

Answer 9

np