Concept: The question tests on the application of Algebra in a DS format
Triangles lying on the same base and between 2 parallel lines have the same areas.
So Area of ΔADC = Area of ΔBDC
Now since Δ DEC is common to both triangles, the remaining area of the 2 triangles will be equal.
Therefore Area of ΔAED = Area of ΔBEC
Hope this helps