Answer :
Four
For example:
Student #1 has 20 (highest)
Student #2 has 6 (lowest)
Student #3 has 16
Student #4 has 8
20 + 6 + 16 + 8 = 50
For example:
Student #1 has 20 (highest)
Student #2 has 6 (lowest)
Student #3 has 16
Student #4 has 8
20 + 6 + 16 + 8 = 50