Đặt $Q = \bigg(1+\dfrac{1}{3}\bigg).\bigg(1+\dfrac{1}{8}\bigg)....\bigg(1+\dfrac{1}{2400}\bigg)$
$ = \dfrac{4}{3}.\dfrac{9}{8}.\dfrac{16}{15}....\dfrac{2401}{2400}$
$ = \dfrac{2.2}{1.3}.\dfrac{3.3}{2.4}.....\dfrac{49.49}{48.50}$
$ = \dfrac{(2.3.4...49).(2.3.4...49)}{(1.2.3...48).(3.4.5...50)}$
$ = \dfrac{49.2}{50} = \dfrac{49}{25}$