Answer:
Since we have 2 pairs of parallel lines, we know that:
x + w + 124° = 180° and z + y + 124° = 180°
=> x + w + 124° + z + y + 124° = 180° + 180°
=> x + w + z + y = 180° + 180° - 124° - 124°
=> x + w + z + y = 112°
Because we know that:
x = y (because they are two alternate interior angles)
z = w (because they are two alternate interior angles as well)
x = w (because we have a bisector of that angle)
=> x = y = z = w
=> 4y = 112°
=> y = 112°/4
=> y = 28°