Home » Aptitude » Average » Question
  1. The average salary of all staff of a school is ₹10,000. The average salary of 20 teaching staff is ₹12,000 and that of non-teaching staff is ₹5000, the number of non-teaching staff will be
    1. 7
    2. 8
    3. 10
    4. 12
Correct Option: B

The average salary of all staff of a school = ₹10,000
Let Number of non-teaching staff = n
∴ 20 × 12000 + n × 5000 = (n + 20) × 10000
⇒ 240000 + 5000n = (n + 20) × 10000
⇒ 240 + 5n = (n + 20) × 10
⇒ 10n – 5n = 240 – 200
⇒ 5n = 40
⇒ n = 40 ÷ 5 = 8



Your comments will be displayed only after manual approval.