一道PREP数学题，没看懂题，希望NN解答

拿铁咖啡

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 10 is closest to X+Y
1) X<500
2) Y<400
答案是E，没看懂题，盼NN解答

离岛

同问

wangshuo_922

500是100的倍数最接近X的，400是100的倍数最接近Y的，那么10的倍数最接近X+Y 是什么?
X可以从451~549吧~Y是351~449，所以X+Y从802~1098 你能确定10的倍数是几么？

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 10 is closest to X+Y
1) X<500
2) Y<400
答案是E，没看懂题，盼NN解答

-- by 会员 拿铁咖啡 (2010/11/1 16:34:59)

拿铁咖啡

恩，应该是这样的，如果用条件1，得到451<x<500,如果用条件2,得到351<y<400，那么802<X+Y<900,可能是10的8倍也可能是9倍，无法确定