求助prep的一道题，马上要考试了，现在心很乱

wenjie87

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

答案是e
我悲剧的连题都读不懂，请NN指教

nioni

帮顶，昨天模考碰到，也是读不懂题，昏……

wenjie87

顶！

yougushizi

500是离x最近的百位数，400是y最近百位数，那么离x+y最近的百位数是多少？
题目说明450<x<550,350<y<450
1）说明450<x<500
2）说明350<y<400
1）+2）：
800<x+y<900
所以不知道是800，还是900
选E

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

答案是e
我悲剧的连题都读不懂，请NN指教

-- by 会员 wenjie87 (2010/8/21 22:17:15)

vesper666

450 < x < 550
350 < y < 450

(1) 450 < x < 500 --- Clearly INSUFF
(2) 350 < y < 400 --- Clearly INSUFF

(1)+(2) =>
800 < x+y < 900

If x+y is 820, the closest multiple of 100 would be 800
Else if x+y is 880, the closest multiple of 100 would be 900

So, INSUFF, hence E  google的。。。上面说 the closest multiple of 100 就是以100取整的意思，比如820的 the closest multiple of 100 是800,860的 the closest multiple of 100 是900，所以上面(1)+(2)后可能是800/900，选E...

双鱼游

x的范围应该是450 < x < 550，y的范围是 350 < y < 450
X = 451 ， Y = 351, 那么X + Y = 802，接近800
X = 499 ，Y = 399, 那么 X + Y = 898 接近900
所以选E

nioni

知道了，多谢两位解惑！

wenjie87

非常感谢！