/in/foo.cc: In function 'int main()':
/in/foo.cc:15:33: error: 'f' was not declared in this scope
   cout<<fixed<<setprecision(2)<<f<<endl; 
                                 ^
/in/foo.cc:14:9: warning: unused variable 'd' [-Wunused-variable]
   float d=c*k;
         ^