请教XDF 蓝皮DS 390题

if Carmen had 12 more tapes,she would have twice as many tapes as Rafael. Does Carmen have fewer tapes than Rafael?
1.Rafael has more than 5 tapes.
2.Carmen has fewer than 12 tapes.

anwser:B

如果选B，算出来是C〈12，R〈12，这就是选B的原因吗？谢谢！

假设C有X个,R有Y个,既有条件是12+X=2Y,这就说明当X=12时,X=Y,且X是偶数.当X<12

时,X<Y;而X>12时,X>Y.要是太抽象,画个图就行~~有时候画个线性图能解决挺多问题的...因

为直观

从条件2可以得出X<12,这个时候,X<Y.所以就有结论啦~~