Question

The surface, or rim, of a canyon is at an altitude of 60 m. On a hike down into the canyon, a party of hikers stops for a rest 137 m below the rim. Then they descend another 57 m. What was their new altitude?

Answer 1

start at 60
hike down 137 below so new is 60-137=-77m

then go down again 57
-77-57=-134

new altitude is -134m