A math contest question says: "Unfortunately, you missed the last math test in your class because you were ill. Your score of a 96 raised the class average from 71 to 72. How many students including yourself are in your class?"
First of all, It says you missed the test while still saying afterwards that you got a score of 96.
And second, how should I find the answer when having such limited information (I don't want the answer I only need help)

Question

A math contest question says: "Unfortunately, you missed the last math test in your class because you were ill.  Your score of a 96 raised the class average from 71 to 72.  How many students including yourself are in your class?"
First of all, It says you missed the test while still saying afterwards that you got a score of 96.
And second, how should I find the answer when having such limited information (I don't want the answer I only need help)