A drawer holds 4 red hats and 4 blue hats,what is the probability of getting exact three red hats or exact 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.
(a)1/2(b)1/8(c)1/4(d)3/8

• probability of taking a particular hat is 1/2 ( 4/8)
  
  Now assume we have 2 take 3 blues and 1 red
  
  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
  
  similarly with red
  
  thus the total is 2*4*1/16 = 8/16 = 1/2
• 12 years agoHelpfull: Yes(21) No(1)
• All the events, being equal in number, are equally likely. As we have to pick up hats from TWO groups, chance is 50-50%, that is probability is 1/2.
• 12 years agoHelpfull: Yes(3) No(1)
• 4/8*3/4=3/8
• 12 years agoHelpfull: Yes(0) No(4)
• can any1 explain further?
• 12 years agoHelpfull: Yes(0) No(0)