Zhang Cun is 0/4km away from the market town/kloc-. One day, my brother went to the market from Zhang Cun. When he walked two kilometers, my brother found that he was missing something and immediately chased him at a speed of 8 thousand meters per hour. When he caught up with his brother, he immediately returned to Zhang Cun at the original speed. His brother had just returned to Zhang Cun when he arrived in the market town. How many kilometers does his brother walk every hour?

Solution: Let my brother's speed be one kilometer per hour.

Little brother's whole journey time = 14/ hour.

The time for the elder brother to catch up with the younger brother =2/(8-a) hours.

Brother's distance at this time =8×2/(8-a)= 16/(8-a) km.

At the same time, distance ratio = speed ratio.

therefore

16/(8-a):[ 14- 16/(8-a)]= 8:a

2a/(8-a)= 14- 16/(8-a)

2a = 14×8- 14a- 16

16a=7× 16- 16

a=7- 1

A=6 km/h

My brother walks 6 kilometers an hour.

for reference only