Question

a) A bag contains 4 r e d marbles, 5 g r e e n marbles, and 6 y e l l o w marbles. If a marble is drawn from the bag, replaced, and another marble is drawn, what is the probability of drawing first a r e d marble and then a y e l l o w marble?

b) A bag contains 5 w h i t e marbles, 6 y e l l o w marbles, and 4 g r e e n marbles. If two different marbles are drawn from the bag , what is the probability of drawing first a w h i t e marble and then a g r e e n marble?

Answer 1

why do you space the names of colors? So weird!

(a) 15 marbles in all, so
P(red,yellow) = 4/15 * 6/15

You try b. Note that since there is no replacement, the number of marbles changes.