By reading the problem you know that the second bag is going to be 21+11% of 21, since it is 11% heavier. So first find what 11% of 21 is. Convert 11% to decimal. Now you have .11, now multiply this by 21. So you’ll have 21x.11=2.31. So you know that the second bag is 2.31 heavier than the first. Add this to the original weight. 21+2.31=23.31. So the large bad weighs 23.31 ounces.