Question

A bag contains 3 red marbles, 4 blue marbles, and 5 white marbles. What is the probability of pulling out first a red, then a blue marble if none are replaced? Ive tried this multiple ways and I cant find out how to do it

Answer 1

we use the multiplication principle
the problem of picking a red is 3/12
once we pick a red there are now only 11 marbles left in the bab
4 of which are blue

Answer 2

so would you do 3/12+4/11