Since, boxes and balls are identical..
So possible orientations:
No 0
=> 7 balls 5 boxes
Now distribute one ball each .. so we are now left with 2 balls and 5 boxes
=> Possible orientations = 1 1 or 0 2
So, 2 ways
One 0
=> 7 balls 4 boxes
Now distribute one ball each .. so we are now left with 3 balls and 4 boxes
=> Possible orientations = 1 1 1 or 1 2 or 0 3
So, 3 Ways
Two 0
=> 7 balls 3 boxes
Now distribute one ball each .. so we are now left with 4 balls and 3 boxes
=> Possible orientations = 1 1 2 or 1 3 or 0 4 or 2 2
So, 4 Ways
Three 0
=> 7 balls 2 boxes
Now distribute one ball each .. so we are now left with 5 balls and 2 boxes
=> Possible orientations = 2 3 or 0 5 or 1 4
So, 3 Ways
four 0
=> 7 balls 1 boxes
So, 1 way
Total Ways = 2+3+4+3+1 = 13 ways
Last edited by
theCodeToGMAT on Tue Jan 21, 2014 2:17 am, edited 1 time in total.
R A H U L
