A man walks at a speed of `6km//hr` for 1 km and `8km//h` for the next 1 km . What is his average speed for the walk of 2 km?

Explanation

Distance traveled is 2 km
Time taken `=(1km)/(6km//hr)+(1km)/(8km//hr)`
`(1/6+1/8)hr=7/(24)hr`
Average speed `=(2kmxx24)/(7hr)=(48)/7 km//hr=7km//hr.`