Let's try to work this through.
#color(blue)("1) Assume 100 g sample and multiply by percentages to find mass of each element")#
#C = 39.99g#
#H = 6.79g#
#O = 53.28g#
#color(blue)("2)Take mass of each element and convert to moles using molar mass from periodic table")#
#"Carbon"->(39.99g)/(1)*(1 "mol")/(12g) = 3.33" mol C"#
#"Hydrogen"->(6.79g)/(1)*(1 "mol")/(1.00g) = 6.79" mol H"#
#"Oxygen"->(53.28g)/(1)*(1 "mol")/(16g) = 3.33" mol O"#
#color(blue)("3)Divide the moles by the smallest mole number of the three values")#
#"Carbon"-> (3.33)/(3.33) = 1#
#"Hydrogen"->(6.79)/(3.33) = 2.03 approx 2#
#"Oxygen"->(3.33)/(3.33) = 1#
#color(blue)("4)Write out the element with their respected whole number mole ratios")#
#C_1H_2O_1#
Answer:#C_1H_2O_1#