Question

1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9+1/10+1/11+1/12的整数部分是几，为啥

Answer 1

原式=1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9+1/10+1/11+1/12
<1/2+1/3+1/4+1/5+1/6+1/6+1/8+1/8+1/10+1/10+1/12
=1/2+1/3+1/4+1/5+1/3+1/4+1/5+1/12
=1/2+1/4+1/4+1/3+1/3+1/5+1/5+1/12
=1+2/3+2/5+1/12
=1+2/3+29/60
<1+2/3+1/2=13/6所以原式<3
同理：
原式=1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9+1/10+1/11+1/12
>1/2+1/3+1/4+1/6+1/6+1/8+1/8+1/10+1/10+1/12+1/12
=1/2+1/4+1/8+1/8+1/3+1/6+1/6+1/10+1/10+1/12+1/12
=1+1/3+1/6+1/6+1/10+1/10+1/12+1/12
=1+1/3+1/3+1/5+1/6
=1+2/3+11/30=1+31/30>2
所以原式>2
所以2<原式<3,所以原式整数部分是2

Answer 2

手算一下，然后得到答案

Answer 3

用小数估算吧。