Sabrina went up 5 floors to her friends house to collect a cake. She went down 8 floors to pass the cake to her cousin. She then went up another 2 floors to look for a friend who stayed on the 10th floor to do homework together. On that floor was Sabrina staying? 19. Fill in the blank A teacher stays back in school to mark test papers. If she marks 10 questions every 5 minutes, she will be going home 20 minutes later. If she marks 14 questions every 5 minutes, she will be able to go home 10 minutes earlier. How many questions does she have to mark? Answer: ______________ questions Chi can ghi dap an thui nhe