According to the topic, the water intake of the water inlet pipe per hour 1/5.

Then 1/5 (2+4) -2x= 1.

6/5-2x= 1

2x= 1/5

x= 1/0

Then1÷110 =10 (hours)

Answer: It takes 10 hour to drain a pool of water just by opening the outlet pipe.

second

Solution: Suppose the purchase price of a jacket is X yuan, then there is

x( 1+50%)×0.8= 168

x= 140

168- 140=28 (yuan)

According to the boss, he actually earned 28 yuan, not 8 yuan, so he was dishonest.