How many integers 'n' exist such that r < n < s ?
1) s - r = 5
2) s and r are not integers
Seems simple, but I do not agree with the OA.
Stmt 1 is INSUFFICIENT as we do not know if s and r are integers or not.
e.g. if s=5, r=0, then there can be 4 different values of n - 1,2,3,4
e.g. if s=5.5, r=0.5, then there can be 5 different values of n - 1,2,3,4,5
Stmt 2 is alone INSUFFICIENT since we have no idea of s and r.
From stmt 1 and 2, n has to be always 5. So, SUFFICIENT.
For me, answer should be C.