A drawer has 4 red hats and 4 blue hats.find the probability of getting excatly 3 blue hats when taking out 4 hats randomly out of the drawer and immediatly returning every hatto the drawer before taking out the next?

• possible outcomes=(RRRR)(RRRB)(RRBR)(RBRR)(BRRR)(BBBR)(BBRB)(BRBB)(RBBB)(RRBB)(BBRR)(RBBR)(BRRB)(RBRB)(BRBR)(BBBB)
  so toatl 16
  n we want exactly 3 blue hats
  so 4/16=1/4 ans.
• 11 years agoHelpfull: Yes(25) No(5)
• It will be 1/2 * 1/2 * 1/2 * 1/2=1/16
• 11 years agoHelpfull: Yes(14) No(12)
• 4c3*4c1/8c4
• 11 years agoHelpfull: Yes(3) No(6)
• 4c1*4c1*4c1/(8c1*8c1*8c1)=1/16
• 11 years agoHelpfull: Yes(2) No(5)
• ans should be 1/8 as every time nos of hat in the drawer is 8 so the proabilty of taking out will be 4c3/8
• 11 years agoHelpfull: Yes(2) No(6)
• using binomial distribution
  
  ans=4C3*(1/2)^3*1/2=1/4
• 11 years agoHelpfull: Yes(2) No(1)
• p(B^B^B)= P(B)*P(B)*P(B)
  = (1/8)*(1/8)*(1/8)
  
• 11 years agoHelpfull: Yes(1) No(7)
• 4c1*4c1*4c1/(8c1*8c1*8c1)=1/16
• 11 years agoHelpfull: Yes(1) No(4)
• 3/4.1/4+1/4.3/4=3/8
• 11 years agoHelpfull: Yes(1) No(3)