Example 7: Missing weighted average
Last Updated On: Fri Aug 28 2026| Section | Students | Average marks |
|---|---|---|
| A | 20 | 70 |
| B | 30 | ? |
| Combined | 50 | 76 |
A "?" marks a missing value.
Question
What is the average mark of Section B?
Solution
- Combined total marks = 50 x 76 = 3,800.
- Section A total marks = 20 x 70 = 1,400.
- Section B total marks = 3,800 - 1,400 = 2,400.
- Section B average = 2,400 / 30 = 80.