Question

If a train runs at 60 km/hr it reaches its destination late by 15 minutes. but, if it runs at 85 kmph it is late by only 4 minutes. find the distance to be covered by the train.

Answer 1

If a train runs at 60 km/hr and reaches destination late by 15 minutes. and if  runs at 85 kmph it is late by only 4 minutes then Distance to be Covered by Train = 37.4 km

Step-by-step explanation:

Let say Distance to be covered = D  km

and Time Taken = T min

Time taken with 60 km/hr speed  =  D/60  hr

= D min

D = T + 15   (as Train reaches 15 Min Late)

=> T = D - 15

Time taken with 85 km/hr speed  =  D/85  hr

= D*60/85 min

= 12D/17

12D/17 = T + 4   (as Train reaches 4 Min Late)

=> T = 12D/17 - 4

Equating

D - 15  = 12D/17 - 4

=> D - 12D/17  = 11

=> 5D = 17 * 11

=> D = 17 * 11/5

=> D  = 37.4

the distance to be covered by the train. = 37.4 km