Mathematics/General Ability MCQs
Topic Notes: Mathematics/General Ability
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
201
How long will a train 200 m long traveling at 54 km/hr take to cross a bridge 340 m long?
Answer:
36 seconds
Total distance = 200 m + 340 m = 540 m. Train's speed in m/s = 54 * (5/18) = 15 m/s. Time taken = Total Distance / Speed = 540 / 15 = 36 seconds.
202
A 250-meter long train crosses a platform of length 150 meters in 20 seconds. What is the speed of the train?
Answer:
72 km/hr
Total distance to be covered to cross the platform = Train length + Platform length = 250 + 150 = 400 meters. Time taken = 20 seconds. Speed = 400 / 20 = 20 m/s. Converting to km/hr: 20 * (18/5) = 72 km/hr.
203
A train passes a 150-meter long bridge in 15 seconds and a standing man in 9 seconds. What is the speed of the train?
Answer:
90 km/hr
Let train length be L and speed be S. L = S * 9. L + 150 = S * 15. Substituting L: 9S + 150 = 15S => 6S = 150 => S = 25 m/s. Converting 25 m/s to km/hr: 25 * 18/5 = 90 km/hr.
204
A train 130 meters long is traveling at 45 km/hr. How long will it take to pass a bridge 245 meters long?
Answer:
30 seconds
Total distance to cover = Length of train + Length of bridge = 130 + 245 = 375 meters. Speed = 45 km/hr = 45 * (5/18) = 25/2 m/s = 12.5 m/s. Time = Distance / Speed = 375 / 12.5 = 30 seconds.
205
A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
Answer:
240 meters
Speed = 54 km/hr = 54 * (5/18) = 15 m/s. The train crosses the man in 20s, so Length of train = 15 * 20 = 300 m. It crosses the platform in 36s, so Distance = 15 * 36 = 540 m. Since Distance = Length of Train + Length of Platform, 540 = 300 + Length of Platform. Platform length = 240 m.
206
A train 120 meters long passes a telegraph pole in 6 seconds. Find the speed of the train.
Answer:
72 km/hr
Speed in m/s = Distance / Time = 120 meters / 6 seconds = 20 m/s. To convert to km/hr, multiply by 18/5. 20 * 18 / 5 = 4 * 18 = 72 km/hr.
207
If a train moving at 90 km/hr takes 12 seconds to cross a signal post, find its length.
Answer:
300 meters
Convert the speed to m/s: 90 * (5/18) = 25 m/s. The distance the train covers while passing a signal post is its own length. Distance = Speed * Time = 25 * 12 = 300 meters. The length of the train is 300 meters.
208
A 200-meter-long train crosses a standing man in 10 seconds. What is the speed of the train in km/hr?
Answer:
72 km/hr
The distance covered is the length of the train (200 meters). Time = 10 seconds. Speed = Distance / Time = 200 / 10 = 20 m/s. Convert this to km/hr by multiplying by 18/5. Speed = 20 * (18/5) = 72 km/hr.
209
A train running at a speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
Answer:
150 meters
Speed = 60 km/hr = 60 * (5/18) = 50/3 m/s. Time taken to cross the pole = 9 seconds. Length of the train is the distance covered in this time. Distance = Speed * Time = (50/3) * 9 = 50 * 3 = 150 meters.
210
A train 150 meters long is moving with a speed of 72 km/hr. How long will it take to cross a pole?
Answer:
7.5 seconds
Convert speed to m/s: 72 * (5/18) = 20 m/s. The distance the train needs to cover to pass the pole is its own length, 150 meters. Time = Distance / Speed = 150 / 20 = 7.5 seconds.