问题
解答题
一个水池，单开甲进水管30分钟能把空池注满； 单开乙排水管40分钟可将满池水排完。当池中无水时，同时打开甲、乙两管，多少分钟才能把池水注满？
答案
解：1÷（
-
）=120（分钟）
搜题请搜索小程序“爱下问搜题”
一个水池，单开甲进水管30分钟能把空池注满； 单开乙排水管40分钟可将满池水排完。当池中无水时，同时打开甲、乙两管，多少分钟才能把池水注满？
解：1÷（ - ）=120（分钟）
Rich or poor, young or old, we all have problems.小题1:We should learn how to deal with our problems. Here are some ways.
Firstly, we should learn to forget.小题2:有时我们会生朋友的气。Good friendships may be lost. Sometimes children have disagreements and decide not to talk to each other.小题3:However, this usually does not last for long. This is an important lesson for us: we can solve a problem by learning to forget.
Secondly, we should regard problems as challenges. Many students often complain about school.小题4:他们有太多的作业要做。They think the rules are too strict. Education is an important part of our development. As young people, it is our duty to try our best to deal with each challenge with the help of our teachers.