The contractor works for 3*5=<<3*5=15>>15 hours
That means he charged 150*15=$<<150*15=2250>>2250
The inspector charged 2250*.8=$1800 less
So the inspector charged 2250-1800=$<<2250-1800=450>>450
So the total amount charged was 250+450+2250=$<<250+450+2250=2950>>2950
#### 2950