there are 2 boxes, one containing 32 red balls and other containing 31 green balls.You are allowed to move the balls between the boxes so that when u choose a ball at random and a ball at random from the chosen box, the probability of getting the red ball is maximised. This maximum probability is

• ans:3/4=0.75
  transfer 31 red balls in another box so that the first box contain 1 red ball and second box contains 31 green+31 red balls.
  1/2*1 + 1/2*31/62 =3/4
• 11 years agoHelpfull: Yes(28) No(3)
• Shifting is allowed therefore shift 31 red balls to Box with green balls which makes it 1 red ball in 1st box and 31 red balls out of total 62 in 2nd box.
  
  While finding probability we will also calculate probability of getting a box that is 1/2 of each.
  
  so probability = (1/2)*1+1/2(31/62)= 3/4
• 11 years agoHelpfull: Yes(18) No(1)
• first to move the balls between two boxes we need to get the red ball only so the probability of choosing the box containing only red balls is 1/2 now choosing the red ball only is 32/63
  so total probability is (1/2)*(32/63)=(16/63)
• 11 years agoHelpfull: Yes(0) No(6)