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
141
A boy rides his bicycle at 15 km/h and reaches school 5 minutes late. If he rides at 20 km/h, he reaches 5 minutes early. Find the distance to the school.
Answer:
10 km
Time difference = 5 mins late + 5 mins early = 10 minutes = 10/60 = 1/6 hours. Distance = [ (15 * 20) / (20 - 15) ] * 1/6 = (300 / 5) * 1/6 = 60 * 1/6 = 10 km.
142
A man crosses a 1200 m long street in 10 minutes. What is his speed in km/h?
Answer:
7.2 km/h
Distance = 1200 m = 1.2 km. Time = 10 minutes = 1/6 hours. Speed = 1.2 / (1/6) = 1.2 * 6 = 7.2 km/h.
143
If a person covers a distance in 40 minutes at 45 km/hr, what should be his speed to cover it in 30 minutes?
Answer:
60 km/hr
Distance = 45 * (40/60) = 30 km. To cover 30 km in 30 minutes (0.5 hours), required speed = 30 / 0.5 = 60 km/hr.
144
A car travelling at a speed of 40 km/hour can complete a journey in 9 hours. How long will it take to travel the same distance at 60 km/hour?
Answer:
6 hours
Distance = Speed * Time = 40 * 9 = 360 km. New Time = Distance / New Speed = 360 / 60 = 6 hours.
145
Two trains of length 150 m and 200 m respectively are running in the same direction. The faster train crosses the slower train in 70 seconds. If the speed of the faster train is 60 km/hr, find the speed of the slower train.
Answer:
42 km/hr
Total distance = 150 + 200 = 350 m. Time = 70s. Relative speed = 350 / 70 = 5 m/s. Convert to km/hr: 5 * (18/5) = 18 km/hr. Relative speed = Speed1 - Speed2. 60 - S2 = 18 => S2 = 42 km/hr.
146
The speed of a train is 72 km/hr. How much distance will it cover in 15 minutes?
Answer:
18 km
Time = 15 minutes = 15 / 60 = 1/4 hours. Distance = Speed * Time = 72 * 1/4 = 18 km.
147
A man covers a distance of 1500 m in 15 minutes. What is his speed in km/hr?
Answer:
6 km/hr
Distance = 1500 m = 1.5 km. Time = 15 minutes = 15 / 60 = 0.25 hours = 1/4 hours. Speed = Distance / Time = 1.5 / 0.25 = 6 km/hr.
148
In what time will a train 100 meters long cross an electric pole, if its speed is 144 km/hr?
Answer:
2.5 seconds
Speed = 144 km/hr = 144 * (5/18) = 40 m/s. Distance = 100m. Time = Distance / Speed = 100 / 40 = 2.5 seconds.
149
A train is traveling at a rate of 45 km/hr. How many seconds will it take to cover a distance of 4/5 km?
Answer:
64
Distance = 4/5 km = 800 meters. Speed = 45 km/hr = 45 * (5/18) = 12.5 m/s. Time = Distance / Speed = 800 / 12.5 = 64 seconds.
150
If a train is 100m long and is running at a speed of 36 km/hr, how much time will it take to cross a pole?
Answer:
10s
Speed = 36 km/hr = 10 m/s. The distance to cross a pole is the length of the train = 100m. Time = 100 / 10 = 10 seconds.