A student has marks 78, 85, 90, and 92 in the four tests, what marks he has to get in the fifth exam to maintain an average of 85 marks?
A student has marks 78, 85, 90, and 92 in the four tests, what marks he has to get in the fifth exam to maintain an average of 85 marks?
Explanation
Step 1: Calculate the total marks needed for an average of 85 over 5 exams.
Total marks needed=Average×Number of exams
Total marks needed=85×5
Total marks needed=425
Step 2: Calculate the sum of the marks from the first four exams.
78+85+90+92=345
Step 3: Subtract the sum of the first four exam marks from the total marks needed.
Marks needed in the fifth exam=425−345
Marks needed in the fifth exam=80