lz~请问你整理的392和 540后面的这题:There are 30 cars with 遮阳板, 20 with power window. How many cars are equipped with both? (1). There are total of 60(?) cars and 15(?) equipped none. (Sufficient, 反正可以求出多少两种都有) (2). Only 45(?) had one equipment (Sufficient)
是不是几乎一样的啊?为什么答案不同呢?
-- by 会员 hjean926 (2011/10/5 22:37:00)
Done. for 392, 条件2Unnecessary one and not enough because 条件#1 is必须的