1.

The average marks obtained by 56 students in an examination is 15. If the mean (average) marks of passed students are 18 and that of failed students are 11, then find the number of students who failed the examination?1. 322. 283. 264. 24

Answer» Correct Answer - Option 4 : 24

Given:

The average marks obtained by 56 students = 15

Mean of passed students = 18

Mean of failed students = 11

Concept used:

Total marks = Average × number of students

Calculations:

The total marks obtained by 56 students = 56 × 15

⇒ 840

Let the number of students failed be 'x'

840 = 11 × x + 18 × (56 - x)

⇒ 840 = 11x - 18x + 1008

⇒ 7x = 1008 - 840

⇒ 7x = 168

⇒ x = 168/7

⇒ x = 24

∴ The number of students failed is 24



Discussion

No Comment Found

Related InterviewSolutions