Consider the following statements about Public Service Commission:
1. The Constitution does not fix the number of members of the Union Public Service Commission.
2. One-half of the members of the UPSC should be persons who have held office under the Government of India or of a state for at least five years.
3. The Chairman and members of the UPSC hold office for a term of five years or until they attain the age of 60 years.
4. Members of Joint Public Service Commission are appointed by the Governors of respective States and hold office till the age of 65 years.
Which of the statements given above is/are correct?