Answer:
-1.2 cm
Explanation:
Let's figure out where the ant is after each step.
Step 1
Start at +3.0
Move left - 1.5
Now at +1.5
Step 2
Start at +1.5
Move right + 4.9
Now at +6.4
Step 3
Start at +6.4
Move left - 7.6
Now at -1.2
The ant is now at -1.2 cm.