巧解工程问题

• 作 者: 马济敏
• 出 处: 小学生学习指导
• 发表日期: 2016年25期
• 关键词: 工作总量 不知道 天后 速度差 工作效率 列式

【例1】一项工程,甲单独做需要8天完成,乙单独做需要12天完成。如果甲先做了3天后,剩下的再由甲、乙合作,还要几天完成?【思路点睛】这是一道工程问题,它的特点是工作总量具体是多少不知道,只告诉我们甲、乙个体各自单独完成这项工程需要的时间,求合作完成这项工程需要的时间。在解题时,我们可以把工作总量假设成1,计算起来比较简单。

[Example 1] A project, A alone need 8 days to complete, B alone need 12 days to complete. If A first done after 3 days, the remaining by A, B cooperation, but also a few days to complete? [Ideas dot eye] This is an engineering problem, which is characterized by the total amount of work is not exactly how many do not know, just tell us A, B individuals to complete the project alone, the time required to complete the cooperation required to complete the project time. When solving problems, we can assume that the total amount of work is 1, which is relatively simple to calculate.