A train starts from station A at 1pm and reaches station B at 3 pm, aftet travelling 108 km. It halts at station B for one hour and then starts for station c which is 42 km fron station B. It reaches station c at 7pm on the same day. The avg speed fo the train for the whole journey from A to C is:
total distance: 108+42 = 150km
total time: 6hr
avg speed: 150km/6hr = 25 km/hr
To find the average speed of the train for the whole journey from A to C, we need to calculate the total distance traveled and the total time taken.
First, let's calculate the total distance traveled. The train traveled 108 km from station A to station B, and then an additional 42 km from station B to station C. Therefore, the total distance traveled is 108 km + 42 km = 150 km.
Next, let's calculate the total time taken. The train started at 1 pm from station A and reached station B at 3 pm, taking a total of 3 pm - 1 pm = 2 hours. It then halted at station B for 1 hour, so the total time taken so far is 2 hours + 1 hour = 3 hours. Finally, the train traveled from station B to station C and took an additional 7 pm - 3 pm = 4 hours.
Therefore, the total time taken for the whole journey from A to C is 3 hours + 4 hours = 7 hours.
Now, we can calculate the average speed by dividing the total distance traveled by the total time taken:
Average speed = Total distance traveled / Total time taken
= 150 km / 7 hours
= 21.43 km/h
Therefore, the average speed of the train for the whole journey from A to C is approximately 21.43 km/h.