It is a learning application of water supply equipment chief engineer examination one-on-one form. For business people with many time constraints, it is most important to promote learning efficiently. Therefore, we developed a five-question question-and-answer application to handle problems in various situations, such as in trains, break times, and lunch breaks. As a result of examining the number of problems that can be handled easily, I came to 5 questions. It is a must-see item for those who work on learning daily.