The following words can be changed into new ones according to a certain pattern. What is the pattern and what are the new words?

1. MOB
2. NUB
3. REV
4. DOC
5. REF

Answer:

The letters ILE can be added to each to make new words:

1. MOBILE
2. NUBILE
3. REVILE
4. DOCILE
5. REFILE