` \frac{1}{8 \times 11} + \frac{1}{11 \times 14} + ... + \frac{1}{605 \times 608}`
`= \frac{1}{3} \times ( \frac{1}{8} - \frac{1}{11} + ... + \frac{1}{605} - \frac{1}{608} )`
`= \frac{1}{3} \times ( \frac{1}{8} - \frac{1}{608} )`
`= \frac{1}{8} \times \frac{75}{608}`
`= \frac{75}{4864}`