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Required probabilty=2/4=1/2

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Askiitians Expert

Sagar Singh

B.Tech, IIT Delhi

total balls = 4

white balls = 2

probablity that  white ball is taken out = 2/4= 1/2

now only 1 white ball is remaining

total balls = 3

probablity that white ball is taken out = 1/3

total probablity = multiplication of both = 1/6

1/6 is the required ans

probability = favourable /total cases   in this case favourable case is choosing 2 white out of 4 white nd total is choosing 2 white out of 2white nd 2 of sum oder colour + choosing 2 white out of 3white and 1 of sum oder colour nd choosing 2 white out of 4 white hence 4c2 / (4c2 + 3c2 + 2c2) calculating it we get 6/11  approve the answer if u have understood the solution 

probability = favourable /total cases   in this case favourable case is choosing 2 white out of 4 white nd total is choosing 2 white out of 2white nd 2 of sum oder colour + choosing 2 white out of 3white and 1 of sum oder colour nd choosing 2 white out of 4 white hence 4c2 / (4c2 + 3c2 + 2c2) calculating it we get 6/10 = 3/5   approve the answer if u have understood the solution ..............

Number of balls = 4

number of balls picked = 2

colour of 2 balls picked = white

the probability that all of them are white is 1

because

1. all 4 could be white

2. 3 white , 1 of another colour

3. 2 white and 2 of one colour each

the number of white balls could be either 2 or 3 or all 4 of them !

so probabilty that all of them are white is 1/2 or 3/4 or 1

since we get 2 white balls out of 2 balls we pick , the probabilty is 2/2 = 1

Please approve