Of the 32 students in a certain class, 15 are in a music club and 20 are in a dance club. If 10 of the students are not in either club, how many of the students are in only one of the two clubs?
A. 5 B. 9 C.10 D. 17 E. 25
答案是 B
很簡單的一題 但是小弟遇到這種題目就沒輒
搜尋也沒有這一題
可以有高手幫忙解答一下嗎
感謝囉