An alcohol is 60% carbon, 13.33% hydrogen and 26.67% oxygen. A.) what is the simplest molecular formula? B.) by another method, the molecular weight was found to be 60. What is the molecular formula

We assume 100 grams and turn those percentages to grams. Get moles.

60 grams carbon (1 mole C/12.01 grams) = 4.995 moles C

13.33 grams hydrogen (1 mole H/1.008 grams) = 13.22 moles H

26.67 grams oxygen (1 mole O/16.0 grams) = 1.66 moles

smallest mole number becomes 1 in empirical formula and divides the others

4.995 moles C/1.66 moles O = 3.009 ( call it 3 C)

13.22 moles H/1.66 moles O = 7.96 ( call it 8 H)

C3H8O

is empirical formula and is as massive as the molecular weight given you in the question. So...

C3H8O

is your simplest molecular formula