Railway Recruitment Board Mathematics — Question 1703
Question
The average age of 30 students is 12 years. When the teacher's age is included, the average increases by 1 year. What is the teacher's age?
- 40
- 45
- 42
- 43
Correct answer
D — 43
Explanation (English)
Total age of students = 30 × 12 = 360. New average = 13 for 31 people → total = 31 × 13 = 403. Teacher's age = 403 − 360 = 43 years.
More Mathematics questions
- Time and Distance — A train running at 60 km/h crosses a 200m platform in 30s. Find length of train.
- Percentage — If 20% of a number is 50, what is 40% of that number?
- Average — Find the average of 12, 18, 24, 30, 36
- Profit and Loss — A shopkeeper sells an item at 20% profit. If CP is ₹500, find SP.
- Simple and Compound Interest — What is the compound interest on ₹10000 at 10% per annum for 2 years?
- Ratio and Proportion — If the ratio of two numbers is 3:5 and their sum is 80, find the larger number.
Practice 1000+ more questions like this
TestPod AI has hand-curated previous-year-questions for SSC, RRB NTPC, IBPS PO, SBI Clerk, and more — with AI explanations in Tanglish, Hinglish, and English.