Calculate Current

Hi... I just started embedde3d C at uni and the prelim work had this question... i dont remeber much from my first year at uni so would appreciate the help.... These are the 2 questions....

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1. How much current will the LEDs draw?
2. How do we make the Z8 supply this current from these pins?

 

OK, to calculate the current in your circuit, I am making a couple of assumptions.

1. To light your LED, you are placing ground or zero volts on the cathode of the LED
2. The voltage drop across the LED is approximately 2 volts

see my full comments here