Question

In a tuition class, there were 15 students. Average marks was 46. Average marks of 7 students was 42. Find the average marks of 8 students.
1. 50.5
2. 49.5
3. 31.6
4. 17.5

Answer 1

Correct Answer - Option 2 : 49.5

 

Given

Number of students = 15

Average marks scored by 15 students = 46

Average marks scored by 7 students = 42

Concept

Average = Sum of all observation/ Number of observation

Calculation

Total marks scored by 15 students = 15 × 46

= 690

Total marks scored by 7 students = 7 × 42

= 294

Total marks scores by 8 students = 690 - 294

= 396

Average marks scored by 8 students = 396/8

= 49.6