Tom has a red marble, a green marble, a blue marble, and three identical yellow marbles. How many different groups of two marbles can Tom take?
+130517 If you mean "distinguishable" groups, we have
(R, G) (R, B) (R, Y)
(B, G) (B, Y)
(G, Y) (Y , Y)
I get seven......
Another way to see this is that from the 4 different colors, we want to choose 2......so C(4.2) = 6
And then, we can combine any 2 of the three yellow marbles into a single identifiable group.
+130517 If you mean "distinguishable" groups, we have
(R, G) (R, B) (R, Y)
(B, G) (B, Y)
(G, Y) (Y , Y)
I get seven......
Another way to see this is that from the 4 different colors, we want to choose 2......so C(4.2) = 6
And then, we can combine any 2 of the three yellow marbles into a single identifiable group.
