Hello I got the wrong answer and I just want to know the correct one since the homework is already finished, Thank you.

Hardeep plans to spend six hours to study for exams in Economics and Geography. The following table shows the maximum mark that he expects to get in each course based on the number of hours spent studying that course. if he spends six hours studying Economics. he expects to get 66 marks in Economics. His opportunity cost of increasing his mark in Economics from 47 to 63 is Hours Spent Hours Spent Studying Studying Geography Economics Mark in Economics 0 20 35 47 57 63 66 6 in Geography. 18 in Geography. 35 in Geography. 60 in Geography. .. 7'8 in Geography