the sum of the parts in this problem is slightly bigger than the total
32.73 + 42.7 = 75.43
Then the percentage composition is not going to be 100% exact but you can calculate some approximation in the following way
%= Part x 100/Total
phosphorous Part = 32.73 g
oxygen Part = 42.7 g
Total = 75.00 g
% phosphorous = 32.73 g x 100 / 75.00 g = 43.64% phosphorous
% oxygen = 42.7 g x 100 / 75.00 g = 56.93 % oxygen
