prog.c: In function 'main':
prog.c:10:22: warning: format '%d' expects argument of type 'int', but argument 2 has type 'double' [-Wformat=]
printf("Cost: %.2d",a*0.6+10);
^
prog.c:14:26: warning: format '%d' expects argument of type 'int', but argument 2 has type 'double' [-Wformat=]
printf("Cost: %.2d",18+(a-30)*0.8+10);
^