- Fossils are the remains of organisms or part of organisms
- Organism remains can be preserved in sedimentary rock
- So, fossils are preserved in sedimentary rock

- Fossils are preserved in sedimentary rock
- If something is preserved in sedimentary rocks, then that something can be found in the sedimentary rock
- Hence, nearly all fossils are found in sedimentary rock

So, nearly all fossils are found in sedimentary rock
Q: Why are most fossils found in sedimentary rocks?
Context:
- If something is preserved in sedimentary rocks, then that something can be found in the sedimentary rock 
- Fossils are the remains of organisms or part of organisms 
- Organism remains can be preserved in sedimentary rock