Formula to create a total based on an IF condition

I sell products to Nurses and Teachers.
In one column I have a drop down, where I flag the product as Nurse or Teacher. In the next column I have the amount (this is variable not constant).
I am trying to write a formual that will total the number of products sold to a Teacher (based on the value in the drop down) and to total the corresponding amount to provide a total for Teachers for the month.

So in logical terms it is. IF product = Teacher, then add product amount to monthly total.

Is this doable without having to separate out my products to separate columns?

tubefeed; Are you able to post a sample file?

I have attempted an attachement but the interface is weird so not sure if it has uploaded or not

Try this, the yellow cells are already MARK in your attachment, is it the result you want

C31 cell formula

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