Concept: The question tests on the ability to solve a Geometry basic problem
Solution:
2 ways of going about this
Method 1: x = 180 - 110 = 70 (Sum of angles on a straight line = 180)
Therefore 70 + 30 + y = 180 (Sum of angles of a triangle = 180)
y = 80
Method 2: Any Exterior angle of a triangle = Sum of opposite interior angles
110 = 30 + y
y = 80
Option D