[問題]Prep一題DS

[Anita0716]

If 500 is the multiple of 100 that is closest to x
and 400 is the multiple of 100 that is cloest to y
which multiple of 100 is closest to x+y
1)x<500
2)y<400

Ans:E

題目就看不懂了
麻煩高手幫忙解答~~

[eiswein]

If 500 is the multiple of 100 that is closest to x
and 400 is the multiple of 100 that is cloest to y
which multiple of 100 is closest to x+y
1)x<500
2)y<400

Ans:E

題目就看不懂了
麻煩高手幫忙解答~~

500是X最接近一百的倍數的數字(有點繞舌..@@) → X介於451~549
400是Y最接近一百的倍數的數字 → Y介於351~449

條件一：不充份，ex:451+351=802(最接近的一百整數為800)；499+449=948(最接近的一百整數為900)
條件二：不充分，理由同上

合併討論：還是不充分，X+Y最接近的一百倍數可以是800也可以是900
所以答案是E

[Anita0716]

連中文都想很久...
終於看懂了

感恩不盡~~