Try following example to understand ternary operator. You can put the following code into a test.c file and then compile it and then run it .
#include <stdio.h>
main()
{
int a , b;
a = 10;
printf( "Value of b is %d\n", (a == 1) ? 20: 30 );
printf( "Value of b is %d\n", (a == 10) ? 20: 30 );
}