[原创]26号，伦敦战s math48, jj

math能有48也靠cd 这2天的jj

废话不多说,能记的我都写下来

1。 DS. x+y is an integer. if y an integer?
(1) x-y is an integer.
(2)x+2y is an integer.

2。n is a two-digit number. if the ten digit of n less than 3?
(1) the unit digit number is 7 more than the ten digit number.
(2) n is twice as the sum of its unit digit number and ten digit number

3。a car takes x gallon per mile on high way and y gallon per mile in city lanes. given that it uses 6 gallons, and travel 170 miles. what is x?

4. 给了一个图，

A                                    /\

                                   /\   /\

                                /\  /\ /\ /\ 

                                   C

A 是起点，c是最后一行的第3个

问，如果从a出发到c,能有多少probability?

rc: 一篇关于恐龙绝种的文章

3。a car takes x gallon per mile on high way and y gallon per mile in city lanes. given that it uses 6 gallons, and travel 170 miles. what is x?

根据已知条件应该可以判断出车还是挺省油的--估计排气量在2。0或者以下。

但判断X的条件是不是还不够啊?大家说说。