If the average of 5 students is given and one student leaves, how is the new average calculated?

Add the leaving student’s marks to the total and divide by 4

Subtract the leaving student’s marks from total sum, then divide by 4

Multiply the original average by 4

None of these

First, calculate the total sum: average × 5

Then subtract the marks of the student who left, and divide the result by 4 to get the new average.