My name is Lucy. I have two good friends, Mary and June. June and I are twelve years old. Mary is thirteen years old. My birthday is November 11th．June's birthday is September 11th ．And Mary's birthday is January 18th. I like red, but they like green. Mary and June are in the same school. They have an Art Festival and a school trip every year, but I only have a Music Festival at my school.

阅读下面古诗，回答问题。
                                                                                         秋夜曲
                                                                                        张仲素
                                                           丁丁漏水夜何长，漫漫轻云露月光。
                                                           秋逼暗虫通夕响，征衣未寄莫飞霜。

①小红说：“男生与女生人数的比是8：7”；

②小明说：“女生人数占全班人数的 $\frac{7}{15}$ ”；

③小芳说：“女生比男生人数少 $\frac{1}{8}$ ”；

④小强说：“女生人数是男生人数的 $\frac{8}{7}$ ．

以上4人的说法中，正确的有（  ）个．