D=1/2x2/3x3/4x...x99/100=1/100
=>D=1/100
\(D=\left(1-\dfrac{1}{2}\right)\times\left(1-\dfrac{1}{3}\right)\times\left(1-\dfrac{1}{4}\right)\times...\times\left(1-\dfrac{1}{100}\right)\)
\(D=\left(\dfrac{2}{2}-\dfrac{1}{2}\right)\times\left(\dfrac{3}{3}-\dfrac{1}{3}\right)\times\left(\dfrac{4}{4}-\dfrac{1}{4}\right)\times...\times\left(\dfrac{100}{100}-\dfrac{1}{100}\right)\)
\(D=\dfrac{1}{2}\times\dfrac{2}{3}\times\dfrac{3}{4}\times...\times\dfrac{99}{100}\)
\(D=\dfrac{1\times2\times3\times...\times99}{2\times3\times4\times...\times100}\)
\(D=\dfrac{1}{100}\)