I need some help with my Calculus 3 homework.

The question:

I think it should be:A manufacturer sells two goods, one at a price of $3000 a unit and the other at a price of $12,000 a unit. A quantity q1 of the first good and q2 of the second good are sold at a total cost of $4000 to the manufacturer.

Express the manufacturer's profit, π, as a function of q1 and q2.

π(q1,q2) = 3000q1 + 12000q2 - 4000

This seems way to easy. I struggled for a while because I believe the sum 4000 should be expressed as (q1+q2). Or am I simply over thinking this?

Thanks.