PP-T2-DS202

[emmaaqua]

The numbers x and y are not integers. The value of x is closest to which integer?

(1) 4 is the integer that is closest to x + y.

(2) 1 is the integer that is closest to x - y.

ANS:E

請教一下~謝謝~^^

[Huang Hsin-Yi]

我是這樣子想
(1) x+y趨近4 有很多組合 如1+3, 2+2,3+1.........insufficient
(2)同(1)的道理

(1)(2)x+y=4 x-y=1 兩式可得y趨近於2/3 ,但x不知

therefore E

[emmaaqua]

好滴~謝謝~^^

[amyliang]

可是(1)+(2)也可以得到x=5/2 不是嗎???
那為什麼不充份咧???

[Huang Hsin-Yi]

沒錯,兩立聯立 x趨近5/2 y趨近2/3
趨近點剛好是中點
所以無法判斷