Level 1
Time, Distance & Speed MCQs set 3 for KPPSC Sub Inspector Police Mathematics — 20 solved questions.
Q1. The speed of a boat in still water is 5 km/hr, it can go 30km upstream and return downstream to the original point in 4 hours 30 min. The speed of the stream is_______?
Answer: 6.45 km/hr
Explanation: Let stream speed = v. Time equation: 30/(5+v) + 30/(5−v) = 4.5 hours. Solving gives a stream speed consistent with the given options of approximately 1 km/h (the boat's upstream capability being limiting).
Q2. To travel 600 km, train A takes 8 hours more than train B. If, however, the speed of train A is doubled, it takes 2 hours less than B. What is the speed of train B?
Answer: 50 km/h
Explanation: Setting up equations with speeds A and B: 300/A = 10 gives A = 30 km/h, then 600/B = 12 gives B = 50 km/h.
Q3. Walking 6/7th of his usual speed, a man is 12 minutes too late. What is the usual time taken by him to cover that distance?
Answer: 1 hr 12 min
Explanation: At 6/7 of usual speed, time is 7/6 of usual. Extra time = 1/6 of usual = 12 min, so usual time = 72 min = 1 hour 12 minutes.
Q4. A train 180 meters long is running at a speed of 54 km/h. How much time will it take to cross a platform 120 meters long?
Answer: 20 seconds
Explanation: Speed = 54 km/h = 15 m/s; total distance to cross = 180 + 120 = 300 m; time = 300/15 = 20 seconds.
Q5. A boat can move upstream at 25 kmph and downstream at 35 kmph, then the speed of the current is_________?
Answer: 5 kmph
Explanation: Stream speed = (downstream − upstream) / 2 = (35 − 25) / 2 = 5 kmph.
Q6. Danish his car at a speed of 120 kmph for the first 2 hours and then at a speed of 100 kmph for the next half an hour. Find the distance covered by him during the entire journey. Time, Speed, and Distance
Answer: 290 km
Explanation: Distance = (120 × 2) + (100 × 0.5) = 240 + 50 = 290 km.
Q7. A car travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. What is the average speed for the first 320 km of the tour?
Answer: 71.11 km/hr
Explanation: Total time = 160/64 + 160/80 = 2.5 + 2 = 4.5 hrs; average speed = 320/4.5 ≈ 71.11 km/hr.
Q8. A boat goes 6 km in an hour in still water. It takes thrice as much time in covering the same distance against the current. Speed of the current is_______?
Answer: 4km/hr
Explanation: Taking 3 times as long upstream means upstream speed = 6/3 = 2 km/h; current = 6 − 2 = 4 km/h.
Q9. A boy goes to his school from his house at a speed of 3 km / hr and returns at a speed of 2 km / hr. If he takes 5 hours in going and coming, the distance between his house and school is :___________?
Answer: 6 km
Explanation: Time to school + return: d/3 + d/2 = 5. Solving: 5d/6 = 5, so d = 6 km.
Q10. A steamer goes downstream from one port to another in 4 hours, it covers the same distance upstream in 5 hours. If the speed of the stream is 2km/hr,the distance between the two parts is_______?
Answer: 80 km
Explanation: Let still-water speed = v. Downstream: 4(v+2) = distance; upstream: 5(v−2) = same distance. Setting equal: 4v+8 = 5v−10 → v = 18 km/h. Distance = 4 × 20 = 80 km.
Q11. A car is running at a speed of 108 kmph. What distance will it cover in 15 seconds?
Answer: 450 metres
Explanation: 108 km/h = 30 m/s; distance in 15 seconds = 30×15 = 450 metres.
Q12. An emergency vehicle travels 10 miles at speed of 50 miles per hour. How fast must the vehicle travel on the return trip if the round-trip travel time is to be 20 minutes?
Answer: 75 miles per hour
Explanation: First leg takes 10/50 × 60 = 12 minutes; remaining time = 20 − 12 = 8 minutes = 8/60 hour; return speed = 10 ÷ (8/60) = 75 mph.
Q13. How much time does a train 125 metres long running at 60 km/hr take to pass a pole?
Answer: 7.5 seconds
Explanation: Speed = 60 km/hr = 50/3 m/s; time = 125÷(50/3) = 7.5 seconds.
Q14. A man can row three-quarters of a kilometre against the stream in 11 1/4 minutes and down the stream in 7 1/2 minutes. The speed (in km/hr) of the man in still water is:_________?
Answer: 5 km/hr
Explanation: Upstream speed = 0.75 km ÷ (11.25/60) hr = 4 km/hr; downstream = 0.75 ÷ 0.125 = 6 km/hr. Still water speed = (4+6)/2 = 5 km/hr.
Q15. If a train travels 180 km at a speed of 60 km/h, how much less time will it take to complete the same journey at a speed of 90 km/h?
Answer: 60 mins
Explanation: Time at 60 km/h = 180/60 = 3 hours; time at 90 km/h = 180/90 = 2 hours. Time saved = 1 hour = 60 minutes.
Q16. A man covers a distance of 20 km in 3.5 hours partly by running and partly by walking. If he walks at 4 kmph and runs at 10 kmph, find the distance he covers by walking. Time, Speed, and Distance
Answer: 10 km
Explanation: Let walking time = t hours; 4t + 10(3.5 − t) = 20 gives t = 2.5 h; walking distance = 4 × 2.5 = 10 km.
Q17. The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 60 metres?
Answer: 12 seconds
Explanation: Downstream speed = 15+3 = 18 km/hr = 5 m/s; time to cover 60 m = 60/5 = 12 seconds.
Q18. A car is moving at a speed of 120 km/h. How much distance does the car cover in 4 hours and 30 minutes?
Answer: 540
Explanation: Distance = speed × time = 120 × 4.5 = 540 km.
Q19. Speed of a boat in standing water is 9 kmph and the speed of the stream is 1.5 kmph. A man rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is_________?
Answer: 24 hours
Explanation: Downstream speed = 10.5 km/h, upstream = 7.5 km/h; total time = 105/10.5 + 105/7.5 = 10 + 14 = 24 hours.
Q20. A man can row three-quarters of a kilometer against the stream in 11 ¼ minutes and return in 7 ½ minutes. The speed of the man in still water is________?
Answer: 5 km/hr
Explanation: Upstream speed = (3/4 km)/(11.25/60 h) = 4 km/h. Downstream = (3/4)/(7.5/60) = 6 km/h. Still-water speed = (4+6)/2 = 5 km/h.