Drawing pictures is an excellent tool. It helps if you can even just picture it in your mind. To get the answer mathematically though:
Question 1.
We want to intercept the outbound track of 300º FROM the NDB at an angle of 45º. The required heading must be either 345º or 255º depending on whether we are north or south of the desired track. Strike out A and B.
Magnetic heading is 070º
Relative bearing to the NDB is 340º
The NDB is 20º left of the nose (360º - 340º)
Therefore, the magnetic bearing TO the NDB is 050º (heading 070º - 20º)
The magnetic bearing FROM the NDB is 230º (050º + 180º)
So we are southwest of the NDB and generally south of the desired track. The heading to intercept the required track must be 345º.