Question

An elevator went up 15 floors, down 9 floors, up 11 floors and down 19 floors. Find the net change

Answer 1

15u + 11u - 9d - 19d = -2d
It went up 26, down 28, a net change of down 2.

Answer 2

The net change would be -2.

Explanation:

The upward change of elevator is represented by positive sign while the downward change represented by negative sign.

Given,

First the elevator goes up 15 floors,

change = + 15,

Then it goes 9 floors down,

change = -9,

Then it goes 11 floors up,

Change = + 11,

Finally, it goes 19 floor down,

Change = - 19

So, the net change = sum of total changes = 15 - 9 + 11 - 19 = -2