A biologist needs at least 40 fish for her experiment. She cannot use more than25 perch or more than 30 bass. Each perch costs $5, and each bass costs $3. HOw many of each fish should she use in order to minimixe the cost?

Pleez help I have no idea what to do.

I don't understand?

She should use 30 bass at $3 and 10 perch at $5
The less perch you have the cheaper it is, right?

I suspect you haven't given the whole question.