Reverse reasoning is reverse reasoning, that is, knowing the result to calculate or estimate the conditions needed to achieve the result.

Xiao Ming needs 10 minutes to get dressed and wash after getting up in the morning, 5 minutes to have breakfast at home, 15 minutes to go to school by bike, and he has to get up before the morning class (8: 00).

In fact, we often use reverse strategy to calculate time, and make arrangements before doing things, so that we will not be in a hurry and do things more orderly.