Answer:
A and B can go into a swap to gain advantage while still borrow at their desired rate. Details are in the explanation part.
Step-by-step explanation:
Both A and B will borrow the same amount in the market, in which:
+ A can borrow from outside, floating at LIBOR + 0.5%. Go to a swap with B to receive LIBOR to B and pay fixed rate of 12% on the borrowed amount. So, total interest rate A has to pay is: Libor - (Libor + 0.5%) - 12.0% = -12.5% or 12.5% fixed => A borrowed fixed at 0.5% lower.
+ B can borrow from outside, fixed at 11%. Go to a swap with A to receive fixed rate of 12% and pay Libor to B on the borrowed amount. So, total interest rate B has to pay is: 12% - Libor -11% = -(Libor - 1%) or Libor - 1% floating => B borrowed floating at 2.5% lower.