Explanation:
I just answered this. how often did you post that question ?
she added 54-48 = 6g.
how many % of 48g are these 6g ?
100% = 48
1% = 100%/100 = 48/100 = 0.48g
how many % are 6g ?
as many as how often 1% (0.48g) fits into 6g :
6 / 0.48 = 12.5%