Ok, so you are close to the answer. Basically, remember that the probability of getting 3 yellows are:
3 purples are:
3 blue are:
Hence, when you combine the terms, you get
hope that clears it up, have fun.
a box contains 15 balls (4 yellow, 5 purple, 6 blue) 3 balls are drawn at random...
without replacement ..calculate P( all 3 balls are of the same color)
The solution says it should be (4/15)^3 + (5/15)^3 +(6/15)^3
I think it should be (4*3*2)/(15*14*13)...Anyone can explain it to me?
Thanks a lot!