Concept: The question tests on applying the basics of Equation in a DS format

Solution:

St (1) Reduces to 2x – y = 1

=>2x = y + 1

If y = 1 then x=1 = y  (Yes ) 

If y = 5 then x  =3 (No)

Hence Insufficient 

 

St (2) Reduces to x-y = 0 

           x = y 

(Yes)

Thus sufficient.


Hence Option (b)