Three boys P,Q and R are to speak at a function along with 5 others. If all of them speak in random order, what is the probability that P speaks before Q and Q speaks before R?

• 6720. cuz no. of ways in which 8 boys can speak is 8!.
  now no. of options for 1st boy = 8, for 2nd boy = 7.. similarly for 4 boy 4. so total is 8*7*6*5*4 = 6720. and as P speaks before Q and Q speaks before R. so total no. of ways is 1. so total = 6720*1 = 6720 answer
  
• 11 years agoHelpfull: Yes(2) No(0)
• 1/8*1/7*1/6
• 11 years agoHelpfull: Yes(0) No(0)