Question

A train travels at a certain average speed for a distance of 63 km and then travels a distance of 72km at an average speed of 6km/hr more than its onginal speed. If it takes 3 hours to complete the total journey, what is its original speed? ​

Answer 1

Answer:

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

Then, 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 72 + X x+6 = 3 = 63x +378 +72x x² + 6x = 3

135x + 378 = 3x² + 18x 3x²-117x-378= 0

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.

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