The annual interest rate is 10%, compounded semi-annually.
Hence, each half-yearly rate \( R = 5\% \), and the number of compounding periods is \( n = 3 \).
Let the original sum be \( P \).
According to the formula for compound interest:
\[ P \times \left(1 + \frac{10}{200}\right)^3 = 18522 \]
Solving for \( P \):
\[ P = 18522 \times \left(\frac{20}{21}\right)^3 \]
\[ P = 18522 \times \frac{8000}{9261} = 16000 \]
\[ \boxed{P = 16000} \]
When $10^{100}$ is divided by 7, the remainder is ?