Question

What would the other number be?

Answer 1

I do not under stand need more info

Answer 2

Really, you'd benefit from drawing this situation.  Plot (1,2).  Notice that y=2 here.  If x remains the same, y moves from 3 units above the horiz. line y = -1 to 3 units below y = -1, and so we have the new point (1,-4).  

Now reflect the pt. (1,-4) about y=1.  Notice that -4 is 5 units beneath y = 1.  So add 5 units to y=1, obtaining y= 6.  The new point is (1,6).