Xiangyang primary school covers a total area of 8.4 hectares, of which teaching buildings account for two-sevenths of the total area of Xiangyang primary school, comprehensive buildings account for one-fourteenth and gardens account for one-twenty. How many hectares are left that are not included in the land use statistics?
Solution: The length of the second segment is 7/ 12, that is to say, the total length of the conductor is regarded as the unit 1, and the second segment is 7/ 12, so the first segment is1-7/12 = 5//kloc-0. Then it's 5/65448. The first section is 7/ 12 = 0.5833m, and the second section is1.4-0.5833 = 0.8167m ... Therefore, the second section of iron wire is longer, with the length of 0.8167-0.5833.