Answer:
1000
Explanation:
If the total score is T and she needs 50% to pass, it means that the pass mark
= 50% * T
= 0.5T
If she fails by 20 marks, it means that her score is the difference between the pass mark and 20
= 0.5T - 20
Given that she gets 480 marks then
0.5T - 20 = 480
0.5T = 500
T = 500/0.5
= 1000
The maximum marks she could have is 1000