i have looked through google and my textbook and have no idea how i can approach this question. it seems pretty easy but i have not learned this material. any help is appreciated thanks.
please show work. and what formulas were used etc.
A zener voltage maintains its rated potential across its terminals only if the the current is within certain limit which is specified by its datasheet.
Here the limit is from 4mA to 40mA.......
Just find out using ohms law the potential applied for which the current through the zener is in that range......
This potential range gives you the answer.......
Try it........