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Question
A bag contains 5 red and 3 blue balls. If 3 balls are drawn at random without replacement the probability of getting exactly one red ball is ______.
Options
`45/196`
`135/392`
`15/56`
`15/29`
Solution
A bag contains 5 red and 3 blue balls. If 3 balls are drawn at random without replacement the probability of getting exactly one red ball is `15/56`.
Explanation:
Given that: Bag contains 5 red and 3 blue balls.
Probability of getting exactly one red ball if 3 balls are randomly drawn without replacement
= P(R) . P(B) . P(B) + P(B) . P(R) . P(B) + P(B) . P(B) . P(R)
= `5/8*3/7*2/6 + 3/8*5/7*2/6 + 3/8*2/7*5/6`
= `30/336 + 30/336 + 30/336`
= `90/336`
= `15/56`
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