December 2009 , Question 1 (a) : Help

Hi

In December 2009 exam , Question 1 (a) , the budget Tuition fee for 8000 students per annum is given as $720,000.

Actual number of students for year ended 30 November 09 is: 6900. And in answers the figure for Tuition material is taken as $92,000.

Can you please tell me how did they came out with $92,000 tuition material cost ?

Thanks