Concept: The question tests on the basics of equations in the format of a Word Problem in DS


Let the price of each donut be a$ and that of a bagel be b$.

St (1)  10a + 6b   = 12.90

  • 5a + 3b  = 12.90 /2 

Thus sufficient 


St (2) Given a = b – 0.15

Thus 5a + 3b

= 5(b-0.15) + 3b 

We do not know the value of a or b and hence Insufficient.


Thus option (A)