a total of 774 doctorates in mathematics were granted to united states citizens by american universities in the 1972-1973 school year , and W of these doctorates were granted to women. the total fo such doctorates in mathematics in the 1986-1987 school year was 362, and w of these were granted to women. if the number of doctorates in mathematics granted to female citizens of the united states by american universities decreased form the 1972-1972 school year to 1986-1987 school year, was the decrease less than 10 percent? 1) 1/10<W/774<1/9 2) W = w+5 答案选C, 题目很长,麻烦大家耐心看看。这是我目前做到比较challenging 的题目了。。 |