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प्रश्न
A bag contains 5 white balls, 6 red balls and 9 green balls. A ball is drawn at random from the bag. Find the probability that the ball drawn is
- a green ball.
- a white or a red ball.
- neither a green ball nor a white ball.
उत्तर
Total number of balls = 5 + 6 + 9 = 20
i. Number of green balls 9, Number of favourable cases
∴ P(Green ball) = `"Number of favourable cases"/"Total number of balls" = 9/20`
ii. Number of white balls 5, Number of red balls 6
Number of favourable cases = 5 + 6 = 11
∴ P(White ball or Red ball) = `"Number of favourable cases"/"Total number of balls" = 11/20`
iii. P(Neither green ball nor white ball) P(Red ball)
= `"Number of Red balls"/"Total number of balls"`
= `6/20`
= `3/10`
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