Answer:
they will reach to their destination faster, its raining or maybe they dont want to walk
Answer: Question 1 is A. C is wrong because without much notice would be informal. B is wrong because posting it on the newspaper it would be visible to everyone even people you don't know.
Question 2 The answer would be B because Madrid is the largest city in Spain. Answer A and C is wrong because both of them are true.
Question 3 the answer is B. Sorry I can't give an explanation I have to go. Let me know if these answers are correct.
Explanation: