Elevator 1 moved up 10 feet from the ground level. its position is labeled as +10. elevator 2 moved down 5 feet from the ground level. its position is labeled as (use the hyphen for negative such as -1)

i believe your answer would be -5 because in the first part of the question, it tells you that ground level is 0. (by saying that when you go up 10 from ground level, you are at postitive (+)10)

so... if you go 5 down from ground level (0), it the same as 0-5 which is -5. hope this helps! :)