In glucose, the hydroxyls at C2, C3 and C4 are aways equatorial and out. (This fact need not not be meorized, as you are told to view a diagram of glucose in the chair conformation.) In galactose, it is stated that the orientation of the H and OH at C4 are opposite that of glucose. Thus in galactose, the the OH must be axial rather than equatorial, and so the H must be equatorial.