A drawer holds 4 red hats. what is the probability of getting exactly 3 red or exactly 3 blue hats when taking out 4 hats randomly out of the drawer and immediately returning every hat to the drawer before taking out the next?
option: 1)1/4 2)3/8 3)1/2 4)1/8

• 
  4c3+4c3/16=1/2
• 10 years agoHelpfull: Yes(10) No(0)
• Probablity of taking out a particular color hat = 4/8 = 1/2
  
  P(BBBR) = (1/2)^4
  P(BBRB) = (1/2)^4
  P(BRBB) = (1/2)^4
  P(RBBB) = (1/2)^4
  total = 4 * (1/2)^4
  
  similary for (RRRB) = 4 * (1/2)4
  
  answer = 8 * (1/2) ^4 = 1/2
• 9 years agoHelpfull: Yes(4) No(0)
• (4c3+4c3)/16=1/2
• 10 years agoHelpfull: Yes(2) No(1)
• there are 4 red and 4 blue hats... so exactly 3 red=(4/8+4/8+4/8+4/8)=1/16
  and for exactly 4 blue hats... same 1/16
  so total probability (1/16+1/16)=1/8 ans
  
• 10 years agoHelpfull: Yes(1) No(12)
• explain ques 1 please
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• 4c3+4c3/16=1/2
• 7 years agoHelpfull: Yes(0) No(0)