问题
选择题
一块面积为1㎡的长方形纸片，第一次裁去它的一半，第二次裁去剩下纸片的一半，如此裁下去，第八次裁完后剩下的纸片的面积是（ ）
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答案
根据题意，第一次剩下的面积为
m2，第二次剩下的面积为1 2
m2，第三次剩下的面积为1 4
m2，则第n次剩下的面积为1 8
m2．1 2n
则第八次剩下的面积为
m2，即1 28
m2．1 256
故选D．
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一块面积为1㎡的长方形纸片，第一次裁去它的一半，第二次裁去剩下纸片的一半，如此裁下去，第八次裁完后剩下的纸片的面积是（ ）
|
根据题意，第一次剩下的面积为
m2，第二次剩下的面积为1 2
m2，第三次剩下的面积为1 4
m2，则第n次剩下的面积为1 8
m2．1 2n
则第八次剩下的面积为
m2，即1 28
m2．1 256
故选D．
| 选词填空。 用方框中短语的恰当形式完成句子。 | |
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