help with chemistry?

Question

an ore contains Fe sub3 O sub4 and no other iron. the iron in a 53.5 gram sample of the ore is all converted by a series of chemical reactions to Fe sub2 O sub3. the mass of Fe sub2 O sub3 is measured to be 30 grams. what was the mass of Fe sub3 O sub4 in the sample of ore? answer in units of grams.

Answer 1

4Fe3O4 + OO2 → 6Fe2O3
x/4(3*55.84 + 4*16) = 30/6(2*55.84 + 3*16)
x/926.08 = 0.03131263
x = 28.997995991983967935871743486974
m = 3*55.84*x/(3*55.84 + 4*16)
m = 20.98196 g

m = 2*55.84*30/(2*55.84 + 3*16)
m = 20.98196 g