Can anyone please let me know that what is going wrong in this approach to solve ques 6.
1/x+1/y+1/z=23/72; x<72
if we take a+b+c=23
where a,b or c cannot be =1 and cannot be same.
Now non-zero values for the three can be 22C2(n-1Cr-1)
We need to subtract the values where either a,b; b,c or a,c are same which will be 11*3
(case when 11,11,1 are the values starting from 1,1,21) . Also we need to subtract values where any one of them is 1. i.e b+c=22 21C1, Now 21C1-2(as two values already subtracted when 1,1,21 cases taken). hence, 22C2=11*21
21C1-2=19*3(Multiply with 3 for all cases) . hence, (11*21-19*3-11*3)/3! as there are 3 variable so for every values there will be 3! ways out of which only one satisfies condn c>b>a.
Some BLUNDER in this approach. Please help!!!!!!!!!!!!!!!!!!!!!!!!!!!1