There is an unlimited stock of blue, red, white, and grey coloured balls. What is the number of ways of selecting 12 balls from the stocks? Request

• Let us say that we have selected 'x1' blue balls, 'x2' red balls, 'x3' white balls and 'x4' grey coloured balls.
  This means, x1+x2+x3+x4 = 12
  Now, for an intance, 1+2+3+6 can be an answer. 0+0+0+12 can also be another answer
  Hence, we need to find the non-negative integral solution for the equation
  x1+x2+x3+x4 = n is
  
  (n+k-1)C(k-1)
  Here, n=12 and k=4
  (12+4-1)C(4-1) = 15C3 = 455
• 7 years agoHelpfull: Yes(13) No(5)
• how it can be define as mentioned above unlimited stock
• 7 years agoHelpfull: Yes(1) No(3)
• lets
  b->blue
  r->red
  w->white
  and
  g->grey
  so according to question----
  b+r+w+g=12 and there will required 3 partition of 12.......so total=12+3
  15! /(12! x 3!)
  =455 ans
• 7 years agoHelpfull: Yes(1) No(3)
• As we have to select blue,red,white,grey balls from unlimited no of stocks
  
  now,for selecting 1st ball we have 4 ways(i.e it can be of blue,red,white,grey),similarly for aal 11 balls
  so ans is
  = 4*4*4*4*4*4*4*4*4*4*4*4
• 5 years agoHelpfull: Yes(1) No(0)
• 12C4 out of 12 ball 4 ball can be selected
• 6 years agoHelpfull: Yes(0) No(0)