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प्रश्न
A bag contains 8 red, 3 white and 9 blue balls. If three balls are drawn at random, determine the probability that all the three balls are blue balls
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उत्तर
Out of 20 balls, three balls can be drawn in 20C3 ways.
∴ Total number of elementary events = 20C3
Out of nine blue balls, three blue balls can be chosen in 9C3 ways.
∴ Favourable number of events = 9C3 ways.
Hence, required probability = \[\frac{^{9}{}{C}_3}{^{20}{}{C}_3} = \frac{9 \times 8 \times 7}{20 \times 19 \times 18} = \frac{7}{95}\]
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| Assignment | ω1 | ω2 | ω3 | ω4 | ω5 | ω6 | ω7 |
| (a) | 0.1 | 0.01 | 0.05 | 0.03 | 0.01 | 0.2 | 0.6 |
| (b) | `1/7` | `1/7` | `1/7` | `1/7` | `1/7` | `1/7` | `1/7` |
| (c) | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.6 | 0.7 |
| (d) | –0.1 | 0.2 | 0.3 | 0.4 | -0.2 | 0.1 | 0.3 |
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