To remove a fraction you simply multiply it by its inverse fraction (take the original fraction and flip it! So, multiply it by 12/1 (which is the same as saying 12).
12(1/12c) = 0.6*12
The 12 cancels out leaving this:
c = 0.6 * 12 c = 7.2
If you don't have or are allowed to use a calculator. To compute that you simply make 0.6 into a fraction then multiply the numerator by 12. .6 is in the tenths place so you can write it like this: 6/10 simplifying it becomes, 3/5
3/5 * 12 = 36/5
Now! That was assuming 1/12c was written like this: (1/12)c = 0.6
If it was actually written like this: 1/(12c) = 0.6 then you'll do this.
Multiply 0.6 by 12c. Which will get you 7.2c. After that you need to get c alone, so you divide both sides by 7.2. Yielding the result: