number of non negative integral solutions for a+b+c = 71 where a>b>c

The answer is 420.
See the solution for a+b+c = 71 is 73C2 = 2628.
These 2628 solutions are non negative integral solutions from which we have to deduct the solutions having 2 equal values.
(0,0,71),(1,1,67).......(35,35,1). These are 36 solutions with each solution arranged in 3 ways. Total = 36*3 = 108
Total unequal sol = 2628-108 = 2520
Now a>b>c can occur in 1 way out of 3! ways.
Required sol = 2520/3! = 420