i want any 3 letter writing topics formal and informal

Few topics on which informal letters can be written are:

Q1. Write a letter to your father from your boarding school, asking him for permission to go for an excursion.

Q2. Write a letter to your friend apologising for not meeting him/her at the airport and explaining your reason for the same.

Q3. Write a letter to your friend describing your annual day function at school with him.

Q4. Write a letter to your friend, letting him know the importance of social networking.

Q5. Write a letter to a friend, discussing on saving wildlife and prohibition on killing and poaching in order to protect the environment.

Q6. A misunderstanding has caused an annoyance with a close friend. Write a letter to your friend explaining the incident to request him/her to solve the matter.