Question

The average marks obtained by 120 students in a class are 35. If the average marks obtained by the passed student was 39 and that of the failed students was 19, then find the number of students who have passed.

1. 100
2. 96
3. 92
4. 106

Answer 1

Correct Answer - Option 2 : 96

Given:

The average marks obtained by 120 students are 35

The average marks obtained by the students who have passed is 39

The average marks obtained by the students who have failed is 19

Concept Used:

Sum = Average × Number of data

Calculation:

The average marks obtained by 120 students are 35

⇒ Total marks obtained by all 120 students = 120 × 35

⇒ 4200

Let, the number of students passed in the examination be x

⇒ Total number of students failed in the examination is (120 – x)

Total marks obtained by the passed student = 39x

Total marks obtained by the students who have failed is 19 × (120 – x)

⇒ 19 × 120 – 19x

⇒ 2280 – 19x

Accordingly,

39x + 2280 – 19x = 4200

⇒ 20x = 4200 – 2280

⇒ 20x = 1920

⇒ x = 96

∴ The number of students who have passed is 96.