Solution Stoichiometry

Can someone please advise me where they are getting the /015grams from for the final answer of 50g/mole. Everything else is pretty straight forward. Thank you!

Hi! From the formula of the base we can conclude that X has an oxidation number of +2. Derive a formula and balance it:
X(OH)2 + 2HCl → XCl2 + 2H2O
using c = m / v, we can find the moles of HCl used: 3 x 0.5 = 1.5 mol
using the ratio 1:2, we find the moles of the base: 1.5/2 = 0.75 mol

total mass = x
mol = 0.75
We don’t know the mr of X but we can find the Mr of the (OH)2 component which would be 34

However since we don’t know the mass of the compound I’m not sure how to find the total Mr. So there’s probably a typo. Someone please let me know!