计算1/3+1/6+1/12+1/24+……+1/384的过程和答案

问题描述:

灰常难

六年级 1个回答 分类:数学 2019-10-30

问题解答:

我来补答

解法一:

1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/384

=1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/192-1/384

=1/3+1/6+1/12+1/24+1/48+1/96+1/96-1/384

=1/3+1/6+1/12+1/24+1/48+1/48-1/384

=1/3+1/6+1/12+1/24+1/24-1/384

=1/3+1/6+1/12+1/12-1/384

=1/3+1/6+1/6-1/384

=1/3+1/3-1/384

=2/3-1/384

=255/384

=85/128

 

解法二:

1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/384

=1/3(1+1/2+1/4+1/8+1/16+1/32+1/64+1/128)

=1/3(1-1/256)×2

=85/128

 

解法三:

1/3+1/6+1/12+1/24+1/48+1/96+1/192+1/384

=(384÷3+384÷6+384÷12+384÷24+384÷48+384÷96+384÷192+384÷384)/384

=(128+64+32+16+8+4+2+1)/384

=255/384

=85/128

 
 
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