## Question

### Solution

Correct option is

7/15

The numbers of ways of placing 3 black balls at 10 place is .

The number of ways in which two black balls are not together is equal to the number of ways of choosing 3 places marked with X out of eight places

X W X W X W X W X W X W X W X

This can be does in ways. Thus, probability of the required event is #### SIMILAR QUESTIONS

Q1

An unbiased die with faces marked 1, 2, 3, 4, 5 and 6 is rolled four times. Out of four face times. Out of four face values obtained, the probability that the minimum face value is not less than 2 and the maximum face value is not greater than 5 is then,

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Q10

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