Give the step-by-step reasoning process and then the final answer. At its current growth rate, a certain plant will be 80 feet tall after a year. If the plant grows at the same rate every month and is currently 20 feet tall, what's its monthly growth rate in feet?
If the plant is currently 20 feet tall, it will have grown by 80 - 20 = 60 feet after a year. Since a year has 12 months, and the tree grows at the same rate every month, the tree grows at 60 / 12 = 5 feet every month.
The final answer: 5.