Question

25. A train covers the first half of the distance between two stations at the speed of 40 km/h and the other half at 60 km/h. Its average speed is (A) 52 km/h (B) 50 km/h (C) 48 km/h (D) 42 km/h​

Answer 1

ANSWER: 48km/hr

Explanation:avg speed = total distance travelled/total time taken

let the total dist be 2x km

time taken for first half motion=x/40 hr

similarly,for second half time=x/60 hr

thus,avg speed=2x/(x/40 +x/60)=48km/hr