1. A man walking at the rate of 5 km/hr crosses a bridge in 15 minutes. What is the length of the bridge (in metres)?
1. 1250
2. 1280
3. 1320
4. 1340
Answer & Explanation Answer:- 1 Explanation :- Speed = 5 km/h = 5 *(5/18) m/s = 25/18 m/s 2. A train travelled at an average speed of 100 km/hr, stopping for 3 minutes after every 75 km. How long did it take to reach its destination 600 km from the starting point? Answer & Explanation Answer:- 1 Explanation :- Time taken to cover 600 km = 6 hours [because train speed is 100 km/hr]
No. of Stops = (600/75) – 1 = 8 – 1 = 7 (Stoppage Time for Last stop exluded) 3. If a train runs at 40 km/hour, it reaches its destination late by 11 minutes. But if it runs at 50 km/hour, it is late by 5 minutes only. The correct time (in minutes) for the train to complete the journey is? Answer & Explanation Answer:- 3 Explanation :- Let the distance be x km 4. Two boys starting from the same place walk at a rate of 5kmph and 5.5kmph respectively. What time will they take to be 8.5km apart, if they walk in the same direction? Answer & Explanation Answer:- 3 Explanation :- 5. 2 trains starting at the same time from 2 stations 200 km apart and going in opposite direction cross each other at a distance of 110 km from one of the stations. What is the ratio of their speeds ? Answer & Explanation Answer:- 1 Explanation :- Total distance is 200 Km
Time = 15 minute = 15*60 seconds = 900 sec
Distance = Speed * Time = (25/18) * 900 = 1250 m/s
1. 6 hrs 21 min
2. 7 hrs 14 min
3. 7 hrs 22 min
4. 6 hrs
Time Spent on stops = 7*3 = 21 minutes
Total time to travel = 6 hrs + 21 minutes
1. 13
2. 15
3. 19
4. 21
5. None of these
Time taken with speed 40 km/h = x/40
Time taken with speed 50 km/h = x/50
Difference between these two time is (11-5) = 6 min.= 1/10 hour
(x/40) – (x/50) = 1/6
(5x – 4x)/200 = 1/6
x = 20, Therefore
Time taken with speed 40 km/h = x/40 = 20/40 = 1/2 hours = 30 min
It is 11 min lat , So correct time = 30-11 = 19 min.
1. 15 hours
2. 16 hours
3. 17 hours
4. 18 hours
5. None of these
The relative speed of the boys = 5.5kmph – 5kmph = 0.5 km/h
Distance between them is 8.5 km
Time = Distance/Speed
Time= 8.5km / 0.5 km/h = 17 hrs
1.11:9
2.13:9
3.17:9
4.21:9
5.None of these
Both trains crossed each other at a distance of 110 km
Therefore, Distance covered by one train =110 km
Distance covered by other train = 90 km
So ratio of their speed = 110 : 90 = 11 : 9