Average mark in Maths — Tables & Charts Aptitude Question
Average mark in Maths: Marks scored by four students out of 100: | Student | Maths | Physics | Chemistry | | --- |… Answer and worked solution on CodeKairo.
- Topic: Tables & Charts
- Section: Data Interpretation
- Difficulty: Medium
- Time target: 75 seconds
Question
Marks scored by four students out of 100:
| Student | Maths | Physics | Chemistry |
|---|---|---|---|
| Amit | 77 | 65 | 82 |
| Bina | 85 | 72 | 68 |
| Chetan | 66 | 90 | 74 |
| Divya | 92 | 58 | 76 |
What is the average mark in Maths across the four students?
Options
- 76
- 78
- 80
- 82
Show the answer and the worked solution
Correct answer: C. 80
Worked solution
- Maths column = 77 + 85 + 66 + 92 = 320.
- Average = 320 ÷ 4 = 80.
Answer: 80.
The idea
Read down the column the question names and ignore the rest of the table. Mixing in another column is the usual slip here.
Shortcut. Measure from 80: −3, +5, −14, +12 sum to zero, so the average is 80.
Common trap. 76 — the option nearest the average of all twelve marks (905 ÷ 12 ≈ 75.4), from averaging the whole table instead of the Maths column.