The percent composition by mass of magnesium mgbr2 (gram formula mass= 184 grams/mole) is equal

a- 24/184 x 100
b- 160/184 x 100
c- 184/24 x 100
d- 184/160 x 100

i really need an answer for this !

Consider the following reaction at equilibrium: c(s)+h2o(g)⇌co(g)+h2(g) predict whether the reaction will shift left, shift right, or remain unchanged upon each of the following disturbances. a) c is added to the reaction mixture. b) h2ois condensed and removed from the reaction mixture c) co is added to the reaction mixture d) h2 is removed from the reaction mixture.