In the following figure, rectangle represents Animators, circle represents Dancers, triangle represents Potters and square represents Mothers. Which set of letters represents Potters who are not Mothers?
Pipes A and B, when working together, can fill an empty tank in 8 hours. If B is stopped after 2 hours, it will take a total of 11 hrs to fill the tank. How long would it take A to fill the empty tank alone?