A bag contains 3 red marbles, 4 blue marbles, and 5 white marbles. What is the probability of NOT pulling out a red marble three times if none are replaced?

Question

parthkohli · Answer

See, one thing, when you pull out one of the marbles, then one marble is decreased from the bag.

Another, the probabilities are multiplied.

anonymous · Answer

So, whats the answer?

parthkohli · Answer

Answer would be:

$\Large \color {purple}{\rightarrow {9 \over 12} * {8 \over 11} * {7 \over 10} }$

Not sure, ask someone.