Answer :

So here is what we have

12 is what we need

out of the 84 we have

so...

12/84= .1428571429

and lets check our work

.1428571429 X 84 = 12

now lets convert it to a percent

.1428571429 X 100 = 14.28571429%

so the answer is 

14.28571429%
12 divided by 84=0.1428. Now 0.1428 times 100% 0.1428X100= 14.28 round up so answer is 14.3%