17. (5 points) Observe the pattern of the following sequence of numbers, the 100th number from left to right is $\qquad$
$$
\frac{1}{2}, \frac{3}{5}, \frac{5}{8}, \frac{7}{11}, \frac{9}{14} \ldots
$$
【Solution】Solution: Numerator: $1+(100-1) \times 2$
$$
\begin{array}{l}
=1+99 \times 2 \\
=199
\end{array}
$$

Denominator: $2+(100-1) \times 3$
$$
\begin{array}{l}
=2+99 \times 3 \\
=299
\end{array}
$$

Therefore, the 100th number from left to right in this sequence is $\frac{199}{299}$. The answer is: $\frac{199}{299}$.