Final answer:
The lemon tree is 16 feet tall.
Step-by-step explanation:
To find the height of the lemon tree, we can set up a proportion using the lengths of the shadows.
Since the height of the slide is 8 feet and its shadow is 15 feet long, we have the ratio: 8/15 = x/30.
Cross-multiplying, we get 15x = 8 * 30.
Solving for x, we find that x = 16 feet. Therefore, the lemon tree is 16 feet tall.