You can
put this solution on YOUR website!
--------> working eqn
We know to Break Even, the total revenue should be zero(0)---> NO GAIN, NO LOST, IT'S BREAK EVEN, right?
We isolate the working eqn,

,

,

These 3 values should equal to zero and isolating them:

-------------> Total Price of the units
To get MINIMUM PRICE PER UNIT:

=$0.08/card -----------> Final Answer
To check, go back working eqn:

--------------> Break even, NO GAIN, NO LOST!
Thank you,
Jojo