How to achieve 57% HI solution ?

Question

How much distilled water is necessary to achieve a solution of exactly 57% w/w from 0,3 mol of hydrogen iodine HI (g.)?

Answer 1

Mass HI = 0.3 mol x 127.904 g/mol = 38.4 g

57 = 38.4 x 100 / x

x = mass solution

x = 67.4 g => mass solute + mass water

mass water needed = 67.4 g - 38.4 = 29.0 g