Question

The average mark of 13 papers is 80. The average marks of the first 7 papers are 84 and that of the last 7 papers is 70. Find the marks obtained in the 7^th paper.
1. 28
2. 19
3. 40
4. 42
5. 38

Answer 1

Correct Answer - Option 5 : 38

Calculation:

The average of 13 papers = 80

∴ the sum of the marks = 13 × 80

⇒ 1040

Average for first 7 papers = 84

∴ The sum = 7 × 84

⇒ 588

Average of last 7 papers = 7 × 70

⇒ 490

∴ the marks obtained in the 7^th paper = (588 + 490) – 1040

⇒ 38

∴ the marks obtained in the 7^th paper are 38.