10. if you break it down it becomes 10. 40 to 20 is 20 20 to 10 is 10 10 to 40 is 30 40 to 20 is 20 now if you take the difference between those and break those down its 20 to 10 is 10 10 to 30 is 20 30 to 20 is 10 now if you break those down its 10 to 20 is 10 20 to 10 is 10 10 is your final answer
