the company earned service revenue of $9000 and sold the entire $7500 of inventory it had for $13,250 for cash

Question

is this operating, investing or financing activity??

Answer 1

^{This activity sounds like that of selling goods and services, which are operating activities.  I don't see any financing or investing activities explained, which usually involves providing money (capital) for others to use to generate a revenue stream, rather than by selling goods and services.}