Six boys and six girls sit in a row randomly.
The probability that all girls sit together is
Total number of ways in which six boys and six girls can be seated in a row = (12)!
Taking all the six girls as one person, seven persons can be seated in a row in 7! ways.
The six girls can be arranged among themselves in 6! ways.
The number of wasy in which six boys and six girls can be seated in a row so that all the girls sit together = 7! × 6!
Required probability = 7!×6!(12)!