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Time and Distance Questions Answers

  • 15. Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?

    1. 9 km/hour
    2. 10 km/hour
    3. 11 km/hour
    4. 12 km/hour
    Answer And Explanation

    Answer: Option D

    Explanation:

    We need to calculate the distance, then we can calculate the time and finally our answer.
    Lets solve this,

    Let the distance travelled by x km
    Time = Distance/Speed

    \begin{aligned}
    \frac{x}{10} - \frac{x}{15} = 2 \\
    \text{[because, 2 pm - 12 noon = 2 hours]} \\

    3x - 2x = 60 \\
    x = 60.

    Time = \frac{Distance}{Speed} \\
    Time @ 10km/hr = \frac{60}{10} = 6 hours

    \end{aligned}
    So 2 P.M. - 6 = 8 A.M
    Robert starts at 8 A.M.

    He have to reach at 1 P.M. i.e, in 5 hours

    So, Speed = 60/5 = 12 km/hr

  • 16. A person travels from P to Q at a speed of 40 km/hr and returns by increasing his speed by 50%. What is his average speed for both the trips ?

    1. 44 km/hour
    2. 46 km/hour
    3. 48 km/hour
    4. 50 km/hour
    Answer And Explanation

    Answer: Option C

    Explanation:

    Speed while going = 40 km/hr
    Speed while returning = 150% of 40 = 60 km/hr

    Average speed =
    \begin{aligned}
    \frac{2xy}{x+y} \\
    = \frac{2*40*60}{40+60} = \frac{4800}{100} \\
    = 48 Km/hr
    \end{aligned}

  • 17. The distance between two cities A and B is 330 Km. A train starts from A at 8 a.m. and travel towards B at 60 km/hr. Another train starts from B at 9 a.m and travels towards A at 75 Km/hr. At what time do they meet?

    1. 10 am
    2. 11 am
    3. 12 pm
    4. 1 pm
    Answer And Explanation

    Answer: Option B

    Explanation:

    Suppose they meet x hrs after 8 a.m.
    then
    (Distance moved by first in x hrs) + [Distance moved by second in (x-1) hrs]
    = 330
    So, 60x+75(x-1) = 330

    x=3.

    So,they meet at (8+3). i.e 11a.m.

  • 18. A man in a train notices that he can count 41 telephone posts in one minute. If they are known to be 50 metres apart, then at what speed is the train travelling?

    1. 60 km/hr
    2. 100 km/hr
    3. 110 km/hr
    4. 120 km/hr
    Answer And Explanation

    Answer: Option D

    Explanation:

    Number of gaps between 41 poles = 40
    So total distance between 41 poles = 40*50
    = 2000 meter = 2 km
    In 1 minute train is moving 2 km/minute.
    Speed in hour = 2*60 = 120 km/hour

  • 19. A train traveled 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.

    1. 6 hours 24 mins
    2. 6 hours 21 mins
    3. 6 hours 18 mins
    4. 6 hours 15 mins
    Answer And Explanation

    Answer: Option B

    Explanation:

    Time taken to cover 600 km = 6 hours [because train speed is 100 km/hr]

    Number of stops =
    begin{aligned}
    frac{600}{75} - 1 = 7 \
    text{Total time on stops =}7*3 = 21 mins

    end{aligned}
    Total time taken by train = 6 hours 21 mins

  • 20. A person travels equal distances with speed of 3 km/hr, 4 km/hr and 5 km/hr and takes a total of 47 minutes. Find the total distane

    1. 3 km
    2. 4 km
    3. 6 km
    4. 9 km
    Answer And Explanation

    Answer: Option A

    Explanation:

    Let the distance be 3x km,
    then,
    \begin{aligned}
    \frac{x}{3} +\frac{x}{4} +\frac{x}{5} = \frac{47}{60} \\
    \frac{47x}{60} =\frac{47}{60} \\
    x = 1
    \end{aligned}
    So total distance = 3*1 = 3 Km

  • 21. A walks around a circular field at the rate of one round per hour while B runs around it at the rate of six rounds per hour. They start at same point at 7:30 am. They shall first cross each other at ?

    1. 7:15 am
    2. 7:30 am
    3. 7: 42 am
    4. 7:50 am
    Answer And Explanation

    Answer: Option C

    Explanation:

    Relative speed between two = 6-1 = 5 round per hour

    They will cross when one round will complete with relative speed,
    which is 1/5 hour = 12 mins.

    So 7:30 + 12 mins = 7:42

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