Lottery balls are numbered and coloured balls. In the famous Lotto, six numbered balls are
drawn at random from 49 balls. In each ticket one needs to guess the six numbers that
would be drawn. If no correct guesses are received the prize money is carried to the next
draw. It is not uncommon to see prize money accumulating to several millions of dollars. An
urn contains m white and n black balls. A ball is drawn at random and is put back into the
urn along with k additional balls of the same colour as that of the ball drawn. A ball is again
drawn at random. The probability of drawing a white ball now:

• (m+n+k-1 C 1)*(m)
• 9 years agoHelpfull: Yes(3) No(1)
• Does not depends on K
• 9 years agoHelpfull: Yes(1) No(1)
• The probability of drawing a white ball increases when the ball drawn at random is white. Similarly if the ball drawn at random is black then the probability of getting a white ball decreases since k additional balls of the same color as that of the ball drawn must be put back into the urn. So, the answer must be "Does not depend on k"
• 9 years agoHelpfull: Yes(0) No(0)
• p(W)=p(w)*p(b/w)+p(w)*p(w/w)
  p(w)=1/2 becoze either black or white
  p(b/w)=m/(m+n+k) [pro of black when white has chhosen
  p(w/w)=m+k/m+n+ k [pro of white when white has chhosen]
• 9 years agoHelpfull: Yes(0) No(0)