Answer:
-15 meters
Step-by-step explanation:
If it goes up 50 meters from the ground, it will be 0+50 which is 50.
Then it says it drops 65 meters into an underground tunnel. So at 50 meters, it dropped 65 meters. That means you subtract this: 50-65, which equals -15 meters because 50 goes into 65 but there is still 15 left, so the 15 is negative.
The ground level is at 0. And we just found out that the tunnel is at -15 meters. To find out how many meters the tunnel is below the ground, just do 0-15, which is still -15 meters. :)
