Explanation:

- The sum triples in 10 years under compound interest. So, the compound interest formula is: \( A = P(1 + r)^n \).

- For it to triple: \( 3P = P(1 + r)^{10} \). This simplifies to \( (1 + r)^{10} = 3 \).

- We need to find how long it takes for the amount to become nine times, i.e., \( 9P = P(1 + r)^n \). Simplify this to \( (1 + r)^n = 9 \).

- Notice \( 9 = 3^2 \), so it can be rewritten as \( ((1 + r)^{10})^2 = 9 \).

- Therefore, \( n = 2 \times 10 = 20 \) years.

- Answer: 1, 20 years