Find the number of ways you can fill a 3*3 grid(with four corners abcd) if u have 3 white marbles and 6black marbles
1.9c3. 2.15c3 3.9c3+6c3. 4.(9c3+6c3)/3!

• It is a 3*3 grid, so there are a total of 9 spaces where you can place the marbles .
  Let us first place the 3 white marbles, that can be done in 9C3 ways. There are 6 spaces available and 6 black marbles are to beplaced in those 6 spaces. So, that can be done in 1 way.
  Hence the answer would be 9C3.
  
• 9 years agoHelpfull: Yes(19) No(1)
• There are 3*3 (total 9) places,and there are total 3+6=9 pics of marble.
  so.we can place in 9! manner,but as there are 3 in same and other 6 are same.
  so,we can place it(9!/6!*3!) way.
  so,the ANS IS 9C3.
• 9 years agoHelpfull: Yes(11) No(0)
• Well as given the total number of spaces to be filled are 9 .
  Now 6 black marbles + 3 white marbles
  spaces to be filled is 9
  hence 9p9 6!3! =84 =9c3
• 9 years agoHelpfull: Yes(0) No(0)
• 1. 9c3
  
  Total blocks on the grid=3*3=9
  Taking 3 white marbles
  we have 9c3
• 9 years agoHelpfull: Yes(0) No(0)