Based on the questions, it looks like we are talking about simple interest, so we use this equation:
Interest = Principle x Rate x Time
I=2000 x 12% x 3
I=2000 x .12 x 3
I=240 x 3
It will cost $720 dollars to borrow the money. You also need to pay back the original $2000, so in total, the cost is $2,720.