请教XDF 蓝皮DS 390题

hexinfo9090

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！

MerisaLees

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~~

hexinfo9090

many&nbsp; thanks !!!!!