Probability

Study Material (PDF)
Self Assesment
Study Material (PDF)
Self Assesment

Click on each question to see answer & solution.

Question No: #111

There are 5 while, 7 red & 3 black balls in a bag. Three balls are drawn from the bag one by one without replacement. What is the probability of no red balls?
Ans: `8/65`
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Question No: #112

There are 5 white, 7 red & 4 black balls in a bag. If 4 balls are drawn one by one (i) with replacement (ii) without replacement, then find the probability of no white balls.
Ans: (i) `(11/16)^4`, (ii) `33/182`
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Question No: #113

An urn contains 8 red & 5 white balls. 3 balls are drawn together for 2 times without replacement. What is the probability of 3 white balls in first drawn & 3 red balls in second drawn?
Ans: `7/420`
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Question No: #114

There are two boxes. Box I contains 4 white, 3 red & 3 blue balls. Box II contains 5 white, 4 red & 3 blue balls. If one ball is drawn randomly from each box, then what is the probability the both balls are of same color?
Ans: `41/120`
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Question No: #115

There are three bags. Bag I contains 3 white & 1 black balls; bag II contains 2 white & 2 black balls; bag III contains 1 white & 3 black balls. One ball is drawn randomly from each bag. What is the probability of getting 2 white & 1 black balls?
Ans: `13/32`
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Question No: #116

In the boxes A, B, C there are 4 reds and 3 black balls, 5 red and 4 black balls, 4 red and 4 black balls respectively. From every box one ball is drawn. What is the probability that the among the three balls 2 balls are red and 1 ball is black.

Question No: #117

An urn contains 4 white and 5 black balls, a second urn contains 5 white and 4 black balls. One ball is transferred from the first to the second urn, then a ball is drawn from the second urn. What the probability that it is white?
Ans: `49/90`
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Question No: #118

An urn A contains 3 white and 5 red balls, a second urn B contains 5 white and 3 red balls. Two balls are transferred from urn A to urn B, then a ball is drawn from the urn B. What the probability that it is red?

Question No: #119

There are two urns. First urn contains 2 red & 3 white balls. Second urn contains 3 red & 5 white balls. A ball is transferred randomly from first urn to second urn and then a ball is drawn randomly from second urn. If the ball drawn is red, then find the probability of transferring a white ball from first urn to second urn.
Ans: `9/17`
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Question No: #120

There are two urns. First urn contains 3 black & 4 white balls. Second urn contains 4 black & 5 white balls. A ball is transferred randomly from first urn to second urn and then a ball is drawn randomly from second urn. If the ball drawn is black, then find the probability of transferring a white ball from first urn to second urn.
Ans: `16/31`
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