What is mass percent `(W/W%)`

What is the mass percent of oxygen in ethanol ?

What is the mass percent of carbon in carbon dioxide ?

If the mass percent of the various elements of a compound is known, its empirical formula can be calculate. What is mass percent?Give its mathematical expression.

If the mass percent of various elements of a compound' is known, its empirical formula can be calculated What is mass percent? Give its mathematical expression

What is the mass percent of the solute in the solution obtained by dissolving 5 g of the solute in 50 g of water ?

4 g of a solute are dissolved in 36 g of water. What is the mass percent of the solution ?