Question 8171: this one i have no clue!!
two marbles are drawn without replacement from a box with 3 white, 2 green, 2 red, and 1 blue marble. find the probability that both marbles are white.
thanks, your a great help!!
Answer by longjonsilver(2297)   (Show Source):
You can put this solution on YOUR website! without replacement, means you pick one and leave it out and then pick another, so at first we have P(White) = 3/8
Once we have done this, we have 2 whites left in a total of 7, so P(second white) = 2/7
Probability of white AND then white is 3/8 x 2/7 which is 3/28.
If you can never remember to multiply or add, just remember, adding 2 fractions together will give a larger (more probable) number. Multiplying 2 fractions gives a smaller number.
In terms of Probability...you pick a white. You pick 2 whites...the 2 whites is less likely to happen, so smaller probability is expected --> multiply.
Hope this helps.
jon.
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