Monday, November 27, 2017

Quant Quiz ► Time Distance & Speed

Q1)-The ratio between the speed of a bus and a train is 15:27, respectively. Also, a car covered a distance of 720 km in 9 h. The speed of the bus is three-fourth of the speed of the car. How much distance will the train cover in 7 h?
760 km
756 km
740 km
None of these
Ans.- B 

Speed of car = 720/9 = 80 km/h
Speed of bus = 3/4 * 80 = 60 km/h
Speed of train = 27/15 * 60 = 108 km/h
Distance covered by train in 7 h = 108 * 7 = 756 km.


Q2)-A 320 m long train crosses a pole in 16 s. It stops five times of duration 18 min each. What time will it take in covering a distance of 576 km?
9 h
19/2 h
17/2 h
37/4 h
Ans.- B


Speed of train = 320 / 16 = 20 m/s = 20 * 18/5 = 72 km/h
Total time of stoppages = 5 * 18 = 90 min = 90/60 = 3/2 h
Time taken = 576/72 = 8 h
Total time taken = 8 + 3/2 = 19/2 h.


Q3)-Total time taken by a boat travelling from A to B and B to A, is 1 h 4 min. Speed of the boat in still water is 12 km/h and speed of the current is 3 km/h. What is the distance between A to B?
6 km
14 km
10 km
4 km
Ans.- A


Speed of upstream = (12 - 3) = 9 km/h
Speed of downstream = (12 + 3) = 15 km/h
Time = 1 h 4 min = 1 + 4/60 = 1 + 1/15 = 16/15
Let the distance between A to B is x km
=> x/9 + x/15 = 16/15
=> (5x + 3x)/45 = 16/15
=> 8x/45 = 16/15
=> x = 6 km.


Q4)-A motor starts with speed of 70 km/h with its speed increasing every 2 hours by 10 km/h. In how many hours will it cover 345 km?
9/4 h
9/2 h
4 h 5 min
Cannot be determined
Ans.- B


Distance covered in first 2 h = 70 * 2 = 140 km
Distance covered in next 2 h = 80 * 2 = 160 km
Distance cover in first 4 h = 160 + 140 = 300 km
Remaining distance = 345 – 300 = 45 km
Time taken = 45/90 = 1/2 h
Total time taken = 4 + 1/2 = 9/2 h


Q5)-A person travels from P to Q at speed of 40 km/h and returns to Q by increasing his speed by 150%. What is his average speed for both the trip?
36 km/h
45 km/h
48 km/h
50 km/h
Ans.- C


Speed of man from P to Q = (150 * 40)/100 = 60 km/h
Average speed = (2 * 40 * 60)/ (40 + 60) = 48 km/h


Q6)-A train crosses a 300 m long platform in 38 s while it crosses a single pole in 18 s. What is the speed of the train?
48 km/h
54 km/h
72 km/h
Cannot be determined
Ans.- B
Let the length of the train is x m
Speed of train = (x + 300)/38 m/s
When the train crosses a single pole, it covers its own length
Speed of train = x/18
=> (x + 300)/38 = x/18
=> 18x + 300*18 = 38x
=> 20x = 300 * 18
=> x = 15 * 18 = 270 km
Speed of train = 270/18 = 15 m/s = 15 * 18/5 = 54 km/h.


Q7)-A bus started its journey from Ramgarh and reached Devgarh in 44 min with its average speed of 50 km/h. If the average speed of the bus is increased by 5 km/h, how much time will it take to cover the same distance?
40 min
38 min
36 min
None of these
Ans.- A
Distance between Ramgarh to Devgarh = 50 * 44/60 = 110/3 km
New speed = 55 km/h
Required time = (110 /3 )/(55) = 2/3 hr = 40 min.


Q8)-The respective ratio between the speed of a car, a jeep and a tractor is 3:5:2. The speed of jeep is 250% of the speed of the tractor which covers 360 km in 12 h. what is the average speed of car and jeep together?
75 km/h
40 km/h
60 km/h
Cannot be determined
Ans.- C
Speed of tractor = 360/12 = 30 km/h
Speed of jeep = 30 * 250/100 = 75 km/h
Speed of car = 3/5 * 75 = 45 km/h
Average speed of car and jeep = (75 + 45)/2 = 60 km/h


Q9)-A man takes 6 h 35 min in walking to a certain place and riding back. He would have taken 2 h less by riding both ways. What would be the time he would take to walk both ways?
4 h 35 min
8 h 35 min
10 h
None of these
Ans.- B
Time taken in walking one way + riding other way = 6 h 35 min
Time taken in riding both ways = 4 h 35 min
Time taken in both ways = 13 h 10 min – 4 h 35 min = 8 h 35 min.


Q10)-A 255 m long train crosses a pole in 6 s. The same train crosses a man running in the same direction in 10 s. What will be the speed of the man?
15 m/s
17 m/s
18 m/s
14 m/s
Ans.- A
Let the speed of man is x m/s
Speed of train = 225/6 = 37.5 m/s
Relative speed when man is running in same direction : (37.5 - x) m/s
=> 225/(37.5 - x) = 10 s
=> 10x = 375 – 225
=> x = 15 m/s.


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