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Two trains for Mumbai leave Delhi at 6 am and 6.45 am and travel at 100 kmph and 136 kmph respectively. How many kilometers from Delhi will the two trains be together:

A. 262.4 km

B. 260 km

C. 283.33 km

D. 275 km

E. None of these

Answer: Option C

Solution(By Examveda Team)

Difference in time of departure between two trains = 45 min. = $$\frac{{45}}{{60}}$$ hour = $$\frac{{3}}{{4}}$$ hour.
Let the distance be x km from Delhi where the two trains will be together.
Time taken to cover x km with speed 136 kmph be t hour
and time taken to cover x km with speed 100 kmph (As the train take 45 mins. more) be
$$ {{\text{t}} + \frac{3}{4}} $$
= $$ {\frac{{4{\text{t}} + 3}}{4}} $$

Now,
100 × $$ {\frac{{4{\text{t}} + 3}}{4}} $$  = 136t
Or, 25(4t + 3) = 136t
Or, 100t + 75 = 136t
Or, 36t = 75
Or, t = $$\frac{{75}}{{36}}$$ = 2.083 hours
Then, distance x km = 136 × 2.083 ≈ 283.33 km.

This Question Belongs to Arithmetic Ability >> Speed Time And Distance

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Comments ( 6 )

  1. Bhaskarjit Kalita
    Bhaskarjit Kalita :
    6 months ago

    since it is asked to find the distance they were together since delhi to let a point m where they meet. we are not asked to find the value of m or the distance from delhi to point m. correct answer will be 208.33

  2. Krrish Rana
    Krrish Rana :
    3 years ago

    Why we consider time as a constant

  3. Henminthang Hangshing
    Henminthang Hangshing :
    4 years ago

    Let A = train with speed 100kmph and
    B = train with speed 136kmph
    And, Let x be the distance from Delhi to the point where the two trains meet.
    Then,
    time take by train A = x÷100 ( time = distance÷speed)
    And,
    time taken by train B = x ÷ 136

    Difference in time taken = 45 minutes

    Now
    (x÷100)-(x÷136) = 45 minutes or 3/4 hr
    Solve for x
    Then you will get x= 283.33 km.
    This is the answer

  4. Mozibur Rahman
    Mozibur Rahman :
    5 years ago

    time deference =45min.=0.75hrs
    1st train go in this period=100*.75=75km
    now relative speed =(136-100)=36km/hr
    so 2nd train meet each other time is=75÷36=2.08
    distance is=136*2.08=283.33km

  5. Tushar Banswal
    Tushar Banswal :
    5 years ago

    Simply you can use formua
    Distance= (S1*S2*T) / (S1-S2)

    where T= difference in time i.e. 45 min means 3/4 hrs. , S1 and S2 are speeds of given

  6. Bhavana Gudikandula
    Bhavana Gudikandula :
    7 years ago

    Already 100 kmph train started before 136kmph train. So when time is taken into point where they meet the time taken by 100kmph train should be less than the other one. But u took in this way. Can u plz explaim???

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