SOLUTION: A bag contains 3 red marbles and 4 white marbles. Two marbles are drawn in succession without replacement. Find the probability the first marble drawn is red and the second is whit

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A bag contains 3 red marbles and 4 white marbles. Two marbles are drawn in succession without replacement. Find the probability the first marble drawn is red and the second is whit      Log On


   

Question 1157705: A bag contains 3 red marbles and 4 white marbles. Two marbles are drawn in succession without replacement. Find the probability the first marble drawn is red and the second is white. Find the probability Both marbles drawn are red.
Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
One two draws w/o replacement, there are four possibilities:
RR
RW
WR
WW
P(RR) = (3/7)(2/6) = 6/42     <<< ans (b)
P(RW) = (3/7)(4/6) = 12/42    <<< ans (a)
P(WR) = (4/7)(3/6) = 12/42
P(WW) = (4/7)(3/6) = 12/42
            total  = 42/42  (ok)