长度一尺2寸5是不是42厘米?

问题描述:

长度一尺2寸5是不是42厘米?

1尺是100/3厘米,1寸是10/3厘米,
所以
1尺2寸5是:100/3+2.5*10/3=125/3,
约是42厘米.