This is my exercise 1:

This is my exercise 2:

This is my exercise 3:

Reflection: I think these exercises are good for me to pay attention to the details of coding. For instance, I’ve learned how important spaces are in conditional executions as I made some mistakes about them. And particularly, exercise 2 is an interesting one, since I need to make sure that the program should first make a decision whether the user enters a right number for the hours, and then make a decision about that of rate afterwards. The order is important in this exercise. And in exercise 3, there are two types of wrong things that users may enter: non-numeric ones and numbers outside 0 and 1, so I need to give different reply to them.