Apply the rules of inference to prove that the conclusion is right.
1. If it rains, then the streets get wet. The streets are wet. If the streets are wet, then people use umbrellas. John is using an umbrella.

Conclusion: It's raining.

Let:
p: It’s raining
q: The streets get wet.
r: People use umbrellas.
s: John is using an umbrella.

2. If it is sunny, then Sarah goes for a run. Sarah did not go for a run. If Sarah doesn't go for a run, then she stays indoors. If Sarah stays indoors, then she reads a book. Sarah reads a book.

Conclusion: It is not sunny.

Let:
p: It is sunny.
q: Sarah goes for a run.
r: Sarah stays indoors.
s: She reads a book.​