Question

英语智力题

In a day at the library, 64 people borrowed books. Twice as many people borrowed a thriller only as borrowed a science fiction only. Three people borrowed a biography only and 11 people borrowed both science fiction and a thriller but not a biography. The same number borrowed a biography and a thriller but no science fiction as borrowed one of each of three types. Twenty-one people did not borrow a thriller. One more person borrowed a science fiction book and a biography book than borrowed a biography only.
How many people borrowed a thriller only?

Answer 1

你那里有答案的吗？我算的是只借惊悚的是28人。
把借书情况分为以下6种情况：
只借惊悚
只借科幻
只借传记
借惊悚和科幻
借科幻和传记
借惊悚和传记

没借惊悚的是21人：只借科幻+只借传记+借科幻和传记
只借传记的人是3人 借科幻和传记的比只借传记的人多一人 所以 借科幻和传记的是4人
21=只借科幻+3+4 所以只借科幻的是21-7=14人
因为只借惊悚的人是只借科幻的两倍 所以只借惊悚的是28人。

你那里有没有答案啊。。。如果我的错了 请回复我正确答案及步骤，谢谢~！！

Answer 2

two

追问

能把解题思路告诉我么

Answer 3

v