11) A person crosses a 600 meter long street in 5 minutes. What is the speed in Km/
- 1) 6.2 km/hr
- 2) 7.2 km/hr
- 3) 8.2 km/hr
- 4) 9.2 km/hr
View Answer
View Explanation
Ans. B
Explanation :
Two things to give attention on this question.
First time is in minutes, we need to change it to seconds to get speed in m/sec, then we need to get the final answer in km/hr.
So lets solve this.
\begin{aligned}
Speed = \frac{Distance}{Time} \\
Distance = 650 meter \\
Time = \text{5 minutes} = 300 sec \\
Speed = \frac{600}{300} = 2 m/sec \\
=> 2*\frac{18}{5} km/hr = 7.2 km/hr
\end{aligned}
12) A train covers a distance in 50 minutes, if it runs at a speed of 48kmph on an average. Find the speed at which the train must run to reduce the time of journey to 40 minute
- 1) 50 km/hr
- 2) 60 km/hr
- 3) 65 km/hr
- 4) 70 km/hr
View Answer
View Explanation
Ans. B
Explanation :
We are having time and speed given, so first we will calculate the distance. Then we can get new speed for given time and distance.
Lets solve it.
Time = 50/60 hr = 5/6 hr
Speed = 48 mph
Distance = S*T = 48 * 5/6 = 40 km
New time will be 40 minutes so,
Time = 40/60 hr = 2/3 hr
Now we know,
Speed = Distance/Time
New speed = 40*3/2 kmph = 60kmph
13) A thief is noticed by a policeman from a distance of 200 m. The thief starts running and the policeman chases him. The thief and the policeman run at the rate of 10 km and 11 km per hour respectively. What is the distance between them after 6 minute
- 1) 50 meter
- 2) 100 meter
- 3) 110 meter
- 4) None of above
View Answer
View Explanation
Ans. B
Explanation :
Relative speed of the thief and policeman = (11 â€“ 10) km/hr = 1 km/hr
Distance covered in 6 minutes =
\begin{aligned}
\frac{1}{60}*6 = \frac{1}{10} \ = 100 meters
\end{aligned}
So distance between them after 6 minutes = 200 - 100
= 100 meters
14) The ratio between the speeds of two trains is 7: 8. If the second train runs 400 kms in 4 hours, then the speed of the first train i
- 1) 83.5 km/hr
- 2) 84.5 km/hr
- 3) 86.5 km/hr
- 4) 87.5 km/hr
View Answer
View Explanation
Ans. D
Explanation :
Let the speeds of two trains be 7X and 8X km/hr.
\begin{aligned}
8X = \frac{400}{4} \=> X = 12.5 Km/hr
\end{aligned}
So speed of first train is 12.5*7 = 87.5 km/hr
15) A cyclist covers a distance of 750 meter in 2 minutes 30 seconds. What is the speed in km/hr of cycli
- 1) 16 km/hr
- 2) 17 km/hr
- 3) 18 km/hr
- 4) 19 km/hr
View Answer
View Explanation
Ans. C
Explanation :
\begin{aligned}
Speed = \frac{Distance}{Time} \Distance = 750 meter \Time = \text{2 min 30 sec} = 150 sec \Speed = \frac{750}{150} = 5 m/sec \
=> 5*\frac{18}{5} km/hr = 18 km/hr
\end{aligned}
16) A man is walking at the rate of 5 km/hr crosses a bridge in 15 minutes. The length of the bridge
- 1) 1000 meters
- 2) 1050 meters
- 3) 1200 meters
- 4) 1250 meters
View Answer
View Explanation
Ans. D
Explanation :
We need to get the answer in meters. So we will first of change distance from km/hour to meter/sec by multiplying it with 5/18 and also change 15 minutes to seconds by multiplying it with 60.
\begin{aligned}
Speed = 5* \frac{5}{18} = \frac{25}{18}m/sec \ Time = 15*60 seconds = 900 seconds \
Distance = Time * Speed \ Distance = \frac{25}{18}*900 = 1250 meter
\end{aligned}
17) A thief is noticed by a policeman from a distance of 200 m. The thief starts running and the policeman chases him. The thief and the policeman run at the rate of 10 km and 11 km per hour respectively. What is the distance between them after 6 minute
- 1) 50 meter
- 2) 100 meter
- 3) 110 meter
- 4) None of above
View Answer
View Explanation
Ans. B
Explanation :
Relative speed of the thief and policeman = (11 â€“ 10) km/hr = 1 km/hr
Distance covered in 6 minutes =
\begin{aligned}
\frac{1}{60}*6 = \frac{1}{10} \ = 100 meters
\end{aligned}
So distance between them after 6 minutes = 200 - 100
= 100 meters
18) Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour
- 1) 8 minutes
- 2) 10 mintues
- 3) 12 minutes
- 4) 14 minutes
View Answer
View Explanation
Ans. B
Explanation :
Due to stoppages, it covers 9 km less.
Time taken to cover 9 km = (9/54) hour
= (1/6)*60 minutes
= 10 minutes
19) 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 directio
- 1) 15 hours
- 2) 16 hours
- 3) 17 hours
- 4) 18 hours
View Answer
View Explanation
Ans. C
Explanation :
In this type of questions we need to get the relative speed between them,
The relative speed of the boys = 5.5kmph â€“ 5kmph
= 0.5 kmph
Distance between them is 8.5 km
Time = Distance/Speed
Time= 8.5km / 0.5 kmph = 17 hrs
20) A Man travelled a distance of 61 km in 9 hours. He travelled partly on foot at 4 km/hr and partly on bicycle at 9 km/hr. What is the distance travelled on fo
- 1) 16 km
- 2) 14 km
- 3) 12 km
- 4) 10 km
View Answer
View Explanation
Ans. A
Explanation :
Let the time in which he travelled on foot = x hour
Time for travelling on bicycle = (9 - x) hr
Distance = Speed * Time, and Total distance = 61 km
So,
4x + 9(9-x) = 61
=> 5x = 20
=> x = 4
So distance traveled on foot = 4(4) = 16 km