Answer:
-30 feet
Step-by-step explanation:
What we know:
The rollercoaster first rose 210 feet, so after rise 1, the height is +210 feet.
After that, it dropped 240 feet. This is greater than the 210 feet it initially rose, so the number is now negative. The height is now -30 feet.
210 - 240 = -|240-210| = -|30| = -30 feet
After that, it rose another 80 feet. That outdoes the eariler -30 feet, so we're back to a positive height. After that rise, the height is now +50 feet.
-30 + 80 = |80 - 30| = |50| = 50 feet
Then the last two drops combine for a 80-foot drop. This is greater than the +50-foot height it was at, so we're back at -30 feet.
50 - 80 -|80 - 50| = -|30| = -30 feet after the last drop