Bài giải:

$\frac{8}{9}\times \frac{15}{16}\times \frac{24}{25}\times ...\times \frac{2499}{2500}$

= $\frac{2\times 4}{3\times 3}\times \frac{3\times 5}{4\times 4}\times \frac{4\times 6}{5\times 5}\times ...\times \frac{49\times 51}{50\times 50}$

= $\frac{2\times 4\times 3\times 5\times 4\times 6\times ...\times 49\times 50}{3\times 3\times 4\times 4\times 5\times 5\times ....\times 50\times 50}$ (giản ước tử và mẫu)

= $\frac{2\times 51}{3\times 50}$

= 17/25