[問題]Prep-T2-Q19 DS

[gozui[origen]]

Set S consists of five consecutive integers, and set T consists of seven consecutive integers. Is the median of the numbers in set S equal to the median of the numbers in set T ?

(1) The median of the numbers in set S is 0.

(2) The sum of the numbers in set S is equal to the sum of the numbers in set T.



Ans: (C)

想請問為什麼(2) alone is insufficient? 謝謝

[eced]

(2)只能知道兩個中位數的關係,ex:5S=7T
要加上(1)的條件S=0 才能知道T=0

[gozui[origen]]

可是可是...
有哪個S和T的set, median不等於0, 但S的和卻等於T的和嗎?

(我以為只有S和T兩組數字只有在median=0的時候, 他們的和才會相等...)

[eced]

set S = {x-2,x-1,x,x+1,x+2}
set T= {y-3,y-2,y-1,y,y+1,y+2,y+3}
sum相等 只要符合5x=7y就可以了 ex: (x,y)=(0,0) (7,5) (14,10) .......

[gozui[origen]]

了解了
非常感謝

[aqboy[origen]]

這題蠻難的....