Final answer:
It will take approximately 3 weeks for the plant to reach 1.5m, using the given growth rate. The same process can be followed to determine the time it takes to reach the other specified heights.
Step-by-step explanation:
To determine how long it will take for the plant to reach certain heights, we need to calculate the number of weeks it will take for the plant to be 10% of its initial height at each stage. Starting with a height of 2m, we can use the formula: final height = initial height * (0.1)^n, where n is the number of weeks. For example, to reach 1.5m, we solve for n: 1.5 = 2 * (0.1)^n. By solving this equation, we find that it will take approximately 3 weeks for the plant to reach 1.5m. Repeat this process for the other heights mentioned.