Calculate the molality of a solution prepared by dissolving 31.6 g of Fe2O3 in 750. g of water

Answer 1

Someone must have made this up out of thin air!
It won't dissolve in water; however, if it would the molarity would be done this way. AND we must assume 75 g of water = 75 mL AND we must assume no volume change upon adding the Fe2O3.
mols = grams/molar mass
M = moles/L soln.

Answer 2

0.007