If you do the problem according to the hint, you first fine the cost per case, which is
... ($235.80/pallet) · (1 pallet)/(36 cases) = $6.55/case
Then the markup per case is
... markup = selling price - cost
... markup = $10.99 - 6.55 = 4.44
Since there are 12 rolls per case, the markup per rool is 1/12 of this value:
... markup/roll = (markup/case) · (1 case)/(12 rolls) = $4.44/12 = $0.37