Question

To get an A in history, a student must score an average of 90 on four papers. Scores on the first three papers were 92, 83, and 88. What is the lowest score that a student can make on the last paper and still get an A?

Answer 1

An average of 90 on four papers means that the total of the four papers must be:
4*90 = 360
If you know the scores of three of the four papers, can you find the minimum of the fourth?

Answer 2

The lowest score the student could make on the last paper and still get an A is 97%. So all the test scores would be: 92, 83, 88, and 97.