An elevator went up 8 floors, then down 6 floors, down 5floors, up to 10 floors down 2floors and up 9 floors. If it stopped on the 15th floors. On what floors did it starts?
10th floor
To determine on which floor the elevator started, we need to keep track of its movements and calculate the net change in the number of floors.
We start by adding the elevators' movements:
Up 8 floors (+8)
Down 6 floors (-6)
Down 5 floors (-5)
Up 10 floors (+10)
Down 2 floors (-2)
Up 9 floors (+9)
Next, we calculate the net change by adding these movements:
(+8) + (-6) + (-5) + (+10) + (-2) + (+9) = 14
The net change is 14 floors. Since the elevator stopped on the 15th floor, we need to subtract one floor from the net change to find the starting floor:
15 - 1 = 14
Therefore, the elevator started on the 14th floor.