One ball is drawn from a box containing 3 red, 2 blue and x green balls. Find the value of x so that the probability of drawing a green ball is double that of red or blue ball.
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One ball is drawn from a box containing 3 red, 2 blue and x green balls.
Find the value of x so that the probability of drawing a green ball is double that of red or blue ball.
5 1 x
––––– = ––– • –––––
5 + x 2 5 + x
5 x
––––– = ––––––
5 + x 10 + 2x
5 2 x
––––– • ––– = –––––
5 + x 2 10 + 2x
10 x
––––– = ––––––
10 + 2x 10 + 2x
x = 10
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