I think that the answer is 1/8 Hope this helps!!!! :D
Explanation:
Percentage ethylene by weight = 57%
Percentage propylene by weight = 43%
Suppose in 100 grams of polymer:
Mass of ethylene = 57 g
Mass of propylene = 43 g
Moles of ethylene = 
Moles of propylene = 
1 mole =
molecules/ atoms
Units of ethylene = 
Units of propylene = 
a) Fraction of ethylene units:

b ) Fraction of propylene units:

8 protons are in the nucleus
The formula for K+ and S-2 is K2S because you need 2 potassium ions to balance out the sulfide ion