RRB NTPC Mathematics 1 — Questions and Answers
Question 1: A train travels 360 km in 4 hours. What is its speed in km/h?
- 80
- 90 (Correct answer)
- 100
- 72
Correct answer: 90
Speed = Distance ÷ Time = 360 ÷ 4 = 90 km/h.
Question 2: The LCM of 12 and 18 is:
- 24
- 36 (Correct answer)
- 54
- 72
Correct answer: 36
The LCM of 12 and 18 is 36 because 36 is the smallest number divisible by both.
Question 3: If a number is increased by 20% and then decreased by 20%, the net change is:
- No change
- 4% decrease (Correct answer)
- 4% increase
- 2% decrease
Correct answer: 4% decrease
After a 20% increase and 20% decrease, the net effect is a 4% decrease (100 × 1.2 × 0.8 = 96).
Question 4: What is the simple interest on ₹5,000 at 8% per annum for 3 years?
- ₹1,000
- ₹1,200 (Correct answer)
- ₹1,500
- ₹800
Correct answer: ₹1,200
SI = (P × R × T) / 100 = (5000 × 8 × 3) / 100 = ₹1,200.
Question 5: The ratio of two numbers is 3:5 and their sum is 64. The larger number is:
- 24
- 40 (Correct answer)
- 32
- 48
Correct answer: 40
The larger number = (5/8) × 64 = 40, since 5 parts out of a total of 8 parts.
Question 6: A man buys an article for ₹400 and sells it for ₹500. His profit percentage is:
- 20%
- 25% (Correct answer)
- 15%
- 30%
Correct answer: 25%
Profit % = (Profit / Cost Price) × 100 = (100/400) × 100 = 25%.
RRB NTPC Mathematics 1
A train travels 360 km in 4 hours.
What is its speed in km/h?