12 is 2% of what? How?

If you would like to know 2% of what is 12, you can calculate this using the following steps:

x ...a number
2% of x is 12
2% * x = 12
2/100 * x = 12     /*100/2
x = 12 * 100/2
x = 12 * 50
x = 600

Result: 2% of 600 is 12.

Aand b is what i think