Human: John is a door-to-door salesman. He visits 50 houses a day. 20% of them buy something from them. Of those that buy something half buy a $50 set of knives and the other half buy a $150 set of knives. How much does he sell a week when he works 5 days a week? Assistant: 
How many houses buy from him per day? ** There are 50*.2=<<50*.2=10>>10 houses buying from him per day
How many houses buy each type of knife set? ** Of those 10/2=<<10/2=5>>5 buy each type of knife set
How much does he get from the cheap set? ** So he gets 5*50=$<<5*50=250>>250 per day from the cheap set
How much does he get from the expensive set? ** He also gets 5*150=$<<5*150=750>>750 from the expensive set
How much does he make in total? ** So he makes a total of 250+750=$<<250+750=1000>>1000 per day
How much does he make in a week? ** That means he makes 1000*5=$<<1000*5=5000>>5000
#### 5000