How to Solve These Two Math Questions: Step-by-Step Explanation Needed

These are terrible questions from a teacher who knows nothing about electronics.

What microcontroller needs 6v?

Most micros have an absolute maximum of 5.5v.

Firstly it shows 200mA and then it talks about 300mA ????

I have never heard of a "variable plug adaptor" Is it infinitely variable or does it have "settings" or "tappings" ?????
No where does it state the REGULATION of the power pack. He has never told you that a small transformer has a very important characteristic that has to be defined before a problem like this can be assessed.


An inductor with 0.1 ohm resistance can have all sorts of different inductances.

Charging a battery at 10 amps is a very complex problem and you simply cannot fiddle around with a few values and expect to produce a battery charger with a 10 amp charge-rate.
A transformer with a 20V output is far too high for a 12v battery charger and the instructor has absolutely no idea what he is doing.