A bag contains 4 red balls, 6 green balls and some white balls. If the probability of not drawing a white ball in one draw be 2/3 the find the number of white balls.

• let number of white balls be x
  to not choose white ball means to select a non-white ball.
  there are 10 non-white balls out of the (4+6+X)
  so the probability is10/(4+6+X) this is equal to 2/3
  
  10/(4+6+X)=2/3 by slvng we get x=5white balls
• 10 years agoHelpfull: Yes(1) No(0)
• Let number of white balls be x.
  P(Drawing white)=x/(x+6+4)
  p(not drawing white)=1-(x/(x+6+4))
  1-(x/(x+6+4))=2/3
  Solving this we get x as 5
  Number of white balls is 5
  
• 10 years agoHelpfull: Yes(0) No(0)
• let no. of white ball
  1-x/6+4+x=2/3
  =>x=5
• 10 years agoHelpfull: Yes(0) No(0)