Time and Distance Questions Answers

  • 8. 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?

    1. 15 hours
    2. 16 hours
    3. 17 hours
    4. 18 hours
    Answer And Explanation

    Answer: Option C

    Explanation:

    In this type of questions we need to get the relative speed between them,
    The relative speed of the boys = 5.5kmph – 5kmph
    = 0.5 kmph

    Distance between them is 8.5 km
    Time = Distance/Speed
    Time= 8.5km / 0.5 kmph = 17 hrs

  • 9. 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
    Answer And Explanation

    Answer: Option 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

  • 10. 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 ?

    1. 11:9
    2. 13:9
    3. 17:9
    4. 21:9
    Answer And Explanation

    Answer: Option A

    Explanation:

    We know total distance is 200 Km
    If both trains crossed each other at a distance of 110 km then one train covered 110 km and other 90 km [110+90=200km]
    So ratio of their speed = 110:90 = 11:9

  • 11. A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.

    1. 200 Km
    2. 222 Km
    3. 224 Km
    4. 248 Km
    Answer And Explanation

    Answer: Option C

    Explanation:

    Let time taken to travel the first half = x hr
    Then time taken to travel the second half = (10 - x) hr

    Distance covered in the the first half = 21x [because, distance = time*speed]
    Distance covered in the the second half = 24(10 - x)

    Distance covered in the the first half = Distance covered in the the second half
    So,
    21x = 24(10 - x)
    => 45x = 240
    => x = 16/3

    Total Distance = 2*21(16/3) = 224 Km [multiplied by 2 as 21x was distance of half way]

  • 12. 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 foot?

    1. 16 km
    2. 14 km
    3. 12 km
    4. 10 km
    Answer And Explanation

    Answer: Option 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

  • 13. In a flight of 600 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes. What is the duration of the flight ?

    1. 3 hours
    2. 2.4 hours
    3. 1.4 hours
    4. 1 hour
    Answer And Explanation

    Answer: Option D

    Explanation:

    Let the duration of the flight be x hours.
    Then
    \begin{aligned}
    \frac{600}{x}-\frac{600}{x + \frac{1}{2}} = 200 \\
    \frac{600}{x}-\frac{1200}{2x+1} = 200 \\
    x(2x+1) = 3 \\
    2x^2 + x - 3 = 0 \\
    => (2x+3)(x-1)=0

    \end{aligned}
    Neglecting the negative value for x we get x = 1

  • 14. A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. Find the average speed for first 320 km of tour.

    1. 70.11 km/hr
    2. 71.11 km/hr
    3. 72.11 km/hr
    4. 73.11 km/hr
    Answer And Explanation

    Answer: Option B

    Explanation:

    We know Time = Distance/speed

    So total time taken =
    \begin{aligned}
    \left(\frac{160}{64}+\frac{160}{80}\right) \\
    = \frac{9}{2} hours \\
    \text{ Time taken for 320 Km = } \\
    320*\frac{2}{9} = 71.11 km/hr
    \end{aligned}