In order to calculate the percent composition of a mixture of salt and sand, we need to have the total mass of the mixture, which, assuming we only have these two mass involved, we will sum both values:
16.32 + 7.44 = 23.76 grams is the total mass of the mixture
23.76 is also 100% of the mass of the mixture, now we can determine the percent composition for each salt and sand:
23.76 = 100%
16.32 = x %
23.76x = 1632
x = 1632/23.76
x = 68.69% is made of salt
Now for sand:
23.76 = 100%
7.44 = x %
x = 31.31% is made of sand
