Question

(4) A train covers a distance of 63 km at its normal speed and then increases the speed by 6 km per hour and covers the remaining 72 km. The total travel time is 3 hours. Finding the common ka of the train.​

Answer 1

Answer:

Let original speed of the train be x km/h.

Time taken to travel 63 km = 63/x hours

New speed = (x + 6) km/hr

Time taken to travel 72 km = 72/(x + 6) hours

According to the question,

63/x + 72/(x + 6) = 3

x2 - 39x - 126 = 0

(x - 42)(x + 3) = 0

x = -3 or x = 42

As the speed cannot be negative, x = 42

Thus, the average speed of the train is 42 km/hr.