Prep-T2-Q155 (DS)

[nomade]

155. 15795-!-item-!-187;#058&010817
If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x + y ?

(1) x < 500

(2) y < 400

請問一下這題題意看不是很懂耶,
If 500 is the multiple of 100 that is closest to x
這是甚麼意思??
500不就是100的倍數了嗎?

[eced]

500 is (the multiple of 100){ that is closest to x}

500是100的倍數裡最靠近X的 450 <= x < 550
400是100的倍數裡最靠近Y的 350 <= y <450
求100的倍數裡最靠近X+Y是多少
(1) x < 500 450 <= x < 550 => 450 <= x <500
(2) y < 400 350 <= y <450 => 350 <= x <400
(1)+(2) 800 <= x+y < 900 => 靠近 x+y的可能是 800 也可能是900 所以都不充分

[Huang Hsin-Yi]

500 is (the multiple of 100){ that is closest to x}

500是100的倍數裡最靠近X的 450 <= x < 550
400是100的倍數裡最靠近Y的 350 <= y <450求100的倍數裡最靠近X+Y是多少
(1) x < 500 450 <= x < 550 => 450 <= x <500
(2) y < 400 350 <= y <450 => 350 <= x <400
(1)+(2) 800 <= x+y < 900 => 靠近 x+y的可能是 800 也可能是900 所以都不充分

紅色字部份實在看不懂

[Huang Hsin-Yi]

隔了兩個月,還是看不懂

[Huang Hsin-Yi]

經過sunnyblue大大的指點
才知 題目是百數進位的描述

[sunnyblue13s]

x*100=451-549.....
y*100=351-449.....
(x+y)*100=802-1098...所以...最接近的值可能會是800 / 900 / 1000 / 1100
無法計算出單一值