PP T2 DS

[chueh]

In a certain class, 72 percent of the male students and 80 percent of the female students have applied to college. What fraction of the students in the senior class are male?

(1) There are 840 students in the class.
(2) 75 percent of the students in the senior class have applied to college.

答案是 (B)
了解意思...本來選的是C......可否替我解答一下...謝謝

[bibbyshiu]

(2)
(M*72% + F*80%) / (M+F) = 75%
可以算出 3M = 5F
進而求出 M / M+F (題目要的)