The key to solving this question easily is to understand the
concept of potential, and sketch out the circuit with that
understanding before solving it in a simple way.
Remember that potential is not the same as potential difference;
potential difference is calculated as the difference in the
potentials. 10V p.d. can be the difference between 10 and 0, or 11
and 1, or 12 and 2, or 8 and -2, etc etc...
Of course, for part (i), we can use Power to solve it as
well.
