Question 132983: (In a jar there are 2 red balls, 3 white balls and 1 green ball).
1.) what is the probability that a green ball will be drawn at 2nd pick?
2.)what is the probability of drawing the same color on both picks?
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website! 1.) It depends on whether or not you put the first pick back into the jar or not before making the second pick. And if you don't put the first pick back into the jar, what color was the first pick?
If you replace the ball every time you select one, then the probability of a given color never changes because you always have the same set of possibilities. So, with replacement, the probability of getting a green ball on the second pick is the same as the first, third, or any other pick, namely: There are 2 + 3 + 1 = 6 balls in the jar, only one of them is green, so the probability that the selection will be green is  .
If you don't replace the ball after you make the first selection, then you have to know whether the first selection was a green ball or not. If it was a green ball, then the probability of a green ball on the second pick is 0 because there aren't any green balls left after picking one on the first try. On the other hand, if the first pick was either red or white, there will be 5 balls left in the jar and one of them is green: 
2.) Again, you have the consideration of whether you replace the first draw or not.
With replacement:
Red: First draw:  , second draw  , both: 
White: First draw:  , second draw  , both: 
Green: First draw: , second draw , both: 
Any duplication: 
Without replacement:
Red: First draw: , second draw (5 balls left, one of them is red), both: 
White: First draw: , second draw  , both: 
Green: First draw: , second draw  , both: 
Any duplication: 
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