1. ambnck; no relation given among m,n,k so it is regular. and Hence DCFL
2. ambnck; if m is even then we have to compare two times (m=n or n=k) and m=k. So it is Not CFL.
3. ambnck; if m=n then n=k. after comparing m and n, stack will be empty so we can't compare again n and k. It is Not CFL.