第30页

信息发布者:
$\frac{2}{63}$
$\frac{1}{63}$
13
$\frac{2}{143}$
$\frac{1}{11}$
$\frac{1}{13}$
$\frac{1}{143}$
​$=\frac {1}{2}×(\frac {1}{3}-\frac {1}{5}+\frac {1}{5}-\frac {1}{7}+\frac {1}{7}-\frac {1}{9}+···+\frac {1}{97}-\frac {1}{99})$​
​$=\frac {1}{2}×\frac {32}{99}$​
​$=\frac {16}{99}$​
因为​$\frac {6}{7}<1<\frac {12}{11}<\frac {13}{11}$​,
所以​$D>B>A>C$​。