Multiply 12 by .15 (15% as a decimal), and you'll get 1.8 meters. You multiply, because it says 15% of 12 meters. Of means to multiply in mathematics, so you multiply .15 by 12.
I agree with @Morax but another way to find out what 15% of 12 meters is, is by multiplying 15x12. You then get 180. Since the original question was to multiply by 15%, you divide 180 by 100. You then get 1.8. The answer is 1.8 meters. This is just another to solve 15% of 12 meters.
You can calculate this by taking 36.72 and dividing it by 0.15 (15%). You would do this because it is the opposite of multiplying an original number by 0.15 (15%) to get 36.72.
