Answer:
-8/3
Explanation:
he had his amount and then he took some away so you subtract then you multiply the amount he has now by the amount he had befor and the amount you took away an then you divide that by how much it weighed so then you multiply that by the cost to get -8/3
that is not how most people do it but it is how i do it and it gets the same answer as the way most people do it.