PP-T2-DS19

[Huang Hsin-Yi]

19. 1251-!-item-!-187;#058&000852
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

想請教(2)選項該如何找到例子推翻?

[Huang Hsin-Yi]

(1)S: x ,x+1,x+2,x+3,x+4
X+2=0 x=-2

(2) x +x+1+x+2+x+3+x+4= x+1+x+2+x+3+x+4+x+5+x+6+x+7
5x+10=7x+28 2x=-18 X=-9
x會隨著 T的數列等級不同而不同,所以 無法確定 s,t median

(1)(2)

x+1+x+2+x+3+x+4+x+5+x+6+x+7=0
7x+28=0 x=-4 median=-3,-2,-1,0,1,2,3