Subject
Quantitative Aptitude
Topic
Probability
A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is:
A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is:
ক)
1/22খ)
3/22গ)
2/91ঘ)
2/77Explanation
Let S be the sample space. Then, n(S) = number of ways of drawing 3 balls out of 15 = 15C3 = (15 x 14 x 13)/(3 x 2 x 1) = 455. Let E = event of getting all the 3 red balls. n(E) = 5C3 = 5C2 = (5 x 4)/ (2 x 1) = 10. P(E) = n(E)/ n(S) = 10/455 = 2/91Related questions
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