Question

A train covers a certain distance at a speed of 40 km/h and the next same distance with a speed of 70 km/h and the next same distance with a speed of 120 km/h. find the average speed?

Q: A train covers a certain distance at a speed of 40 km/h and the next same distance with a speed of 7

Since the distance is same in all the conditions. Therefore, Average speed = 3xyz/(xy + yz + zx) Average speed = 3 x 40 x 70 x 120/(40 x 70 + 70 x 120 + 40 x 120) Average speed = 3 x 40 x 70 x 120/(2800 + 8400 + 4800) = 1008000/16000 = 63 km/hr

A 60 km/hr

B 63 km/hr

C 31.5 km/hr

D 75 km/hr

E 90 km/hr

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Question

A train covers a certain distance at a speed of 40 km/h and the next same distance with a speed of 70 km/h and the next same distance with a speed of 120 km/h. find the average speed?

Solution

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