Amt of time from 07 00 (Mon) to 16 35 (Wed) is 57hours and 35minutes.

No. of days (sets of 24 hours) in 57hours and 35minutes –> 2sets R 9hours and 35minutes

Total paid (without GST) = 2 x $78.50 + 10 x $7 = $227

Total paid (with GST) = 107% x $227 = $242.89

Hope you understand and good luck with your exams!