`1`$\dfrac{1}{7}$ `× 1`$\dfrac{1}{8}$ `× 1`$\dfrac{1}{9}$ `× 1`$\dfrac{1}{10}$ `× .... × 1`$\dfrac{1}{50}$
`=` $\dfrac{8}{7}$ `×` $\dfrac{9}{8}$ `×` $\dfrac{10}{9}$ `×` $\dfrac{11}{10}$ `× .... ×` $\dfrac{51}{50}$
`=` $\dfrac{8 × 9 × 10 × 11 × ... × 51}{7 × 8 × 9 × 10 × ... × 50}$
`=` $\dfrac{51}{7}$