12 students sit exam with a max score of 100. The average of 12 scores was 95. What is the minimum mark a student could have scored?

Average score = 95, thus combined score of 12 students is 95x12=1140.

If 11 students score 100, then their combined score is 11x100=1100. So the last student must score at least 40. The minimum is then 40.