GRE
$$\frac{n+1}{n+2}$$
$$\frac{1}{2}$$
S+1
T
$$k$$
$$m$$
The number of copies of Magazine X that were sold last month at the subscription price
Twice the number of copies of Magazine X that were sold last month at the cover price
$$\frac{x}{y}$$
$$\frac{x+c}{y+c}$$
25000 +道题目
236本备考书籍