Question

If a train runs at 40km per hour, it reaches its destination late by 12 minutes, but if it travels at a speed of 60 km per hour it reaches its destination 3 minutes early.Find the correct time taken by the train to complete it's journey ​

Answer 1

Answer:

Let the correct time taken by the train to complete its journey be t mins.

Then, the given situation can be representedas:

Speed (km per hour) 40 50

Time (min) (t + 11) (t + 5) Respectively.

It can be seen that, increase in the speed decreases the time taken.

Therefore, the two quantities are inversely proportional.

40(t + 11) = 50(t + 5)

40t + 440 = 50t + 250

50t – 40t = 440 – 250

10t = 190

t = 19

Thus, the correct time for the train to complete its journey is 19 mins.

Answer 2

Answer:

33 min

Step-by-step explanation:

Speed = distance / time

let the original time taken be x

d = 40(x+12)   --------(1)

d = 60(x-3)     --------(2)

solving eq 1 and 2

20x = 660

x = 33 min