help with some math problems, introduced in physics class

Hello!

I need some problems solved for physics class which is soon, so I'm taking my chances here. If no one answers before, I still want to learn how it's done :D

So here we go.

*Translation from Danish:*

On the motor of a turn-bench it says that it's max horsepower if 2.0 HK. When in use at work it uses 1.2 HK. The work takes 5 minutes.

a. How much Joules does the motor use?

b. How much kWh does the motor use?

c. What's the cost of the energy, when 1 kWh costs 1,50 kr.?

I DO NOT just want answers, I want to learn and learn how it's done :D So if anyone has the time and feels like helping out, please do so! It WILL be much appreciated!

Thanks in advance!