Answer:
Step-by-step explanation:
Step one:
Speed uphill 100meters per hour
Speed on flat ground 120 meters per hour
Speed uphill 150 meters per hour.
Required
The average speed.
Step two:
To get the average speed, let us add all the individual speeds and divide by 3(three different speeds), then multiply the result by 2(the return trip)
Average speed= (100+120+150)*2/3
Average speed= 740/3
Average speed= 246.6 meters per hour