Question

a train after speed of 30 kilometre per hour in the first 15 minutes with a speed of 40 kilometre per hour in the next 15 minutes and then the speed of 60 km per hour in the last 30 minutes calculate the average speed of train journey

Answer 1

Explanation:

30× 15/6=

7.50km

40× 15/60=10 km

60×15/60=

15km

1st 15.min. increase=10

2nd = 20

therefore 3rd = 30

60+30=

90km

90×15/60=

22.50km

4th= 40

90+40 =130

130×15/60=

32.5km

1. 7.50+15+90+