ProbabilityHard
Question
Seven white balls and three black balls are randomly placed in a row. The probability that no two black balls are placed adjscently, equals
Options
A.

B.

C.

D.

Solution
The number of ways of placing 3 balls without any restriction is 10C3 . Since, we have total 10 places of putting 10 balls in a row . Now the number of ways in which no two black balls put together is equal to the number of ways of choosing 3 places marked ′
′ out of eight places.

This can be done in 8C3 ways.
∴ Rwquired probability
′ out of eight places. 
This can be done in 8C3 ways.
∴ Rwquired probability

Create a free account to view solution
View Solution FreeMore Probability Questions
If the probabilities of three persons A, B & C hitting a target are 3/5, 2/5 and 3/4 respectively. If they hit at a time...A committee consists of 9 experts taken from three colleges, A, B and C; of which 2 are from A,3 from B and 4 from C. If...If A and B are two events such that P (A) = 1/3, P(B) = 1/4 and P (A B)= 1/5, then P =...An instrument consists of two units. Each unit must function for the instrument to operate. The reliability of the first...The probability that an event A happens in one trial of an experiment is 0.4. Three independent trials of the experments...