Speeds of two trains = 30 kmph and 58 kmph
=> Relative speed = 58 - 30 = 28 kmph = 28 x 5/18 m/s = 70/9 m/s
Given a man takes time to cross length of faster train = 18 sec
Now, required Length of faster train = speed x time = 70/9 x 18 = 140 mts.
Average speed = Total distance / Total time.
Total distance traveled by Joel = Distance covered in the first 3 hours + Distance covered in the next 5 hours.
Distance covered in the first 3 hours = 3 x 60 = 180 miles
Distance covered in the next 5 hours = 5 x 24 = 120 miles
Therefore, total distance traveled = 180 + 120 = 300 miles.
Total time taken = 3 + 5 = 8 hours.
Average speed = 300/8 = 37.5 mph.
we know that 1 mile = 1.6 kms
=> 37.5 miles = 37.5 x 1.6 = 60 kms
Average speed in Kmph = 60 kmph.
Speed on return trip = 150% of 50 = 75 km/hr.
Average speed = (2 x 50 x 75)/(50 + 75) = 60 km/hr.
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