A tree is at present 9 feet tall. If every year it grows \(\frac{1}{9}\)th of its height, what will be the height of the tree after three years?

Each year the height is multiplied by $\frac{10}{9}$: $9 \times \left(\frac{10}{9}\right)^3 = \frac{1000}{81} \approx 12.345$ feet, so 12.34 feet is the closest option. Growth is on the new height each year, so adding 1 foot a year (12 feet) understates it.