Question

[(1-1/2)(1-1/3)...(1-1/10)]^-1

Answer 1

$\left[\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\ldots\left(1-\frac{1}{10}\right)\right]^{-1}=\left(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\ldots\frac{8}{9}\cdot\frac{9}{10}\right)^{-1}=\left(\frac{1}{10}\right)^{-1}=10$