Question 9
What is the value of the product of the $9$ factors below?
$$
\begin{aligned} &\left(1 - \tfrac12\right)\left(1 - \tfrac13\right)\left(1 - \tfrac14\right) \cdots \\ &\quad {}\cdot \left(1 - \tfrac{1}{10}\right) \end{aligned}
$$
$$
\begin{aligned} &\left(1 - \tfrac12\right)\left(1 - \tfrac13\right)\left(1 - \tfrac14\right) \cdots \\ &\quad {}\cdot \left(1 - \tfrac{1}{10}\right) \end{aligned}
$$