c program

The following code will do what is requested, including minor spelling corrections. However, Yahoo modifies some single characters (example " in the question), so some adjustments may have to be made.

/* a backslash is used to print special characters, such as the double quote */
printf("a \"string\" is made up of characters\n");
/* % has to be doubled to distinguish from the format specifications */
printf("the price is increased by 10%%\n");
/* the backslash has to be "protected" by another backslash */
printf("the character \\n is to start a new line\n");
/* Again, % has to be doubled to print properly */
printf("%%5.2f means the minimum length is 5 and decimal place is 2\n");
/* nothing needs to be done to print the single quote */
printf("an example of charcater is 'A'\n");