Find next: 1, 4, 9, 16, 25, ?

Statements: No pen is a book. Some books are papers. All papers are files. Some files are folders. Conclusion: Some pens are files. Is this conclusion valid?

The process by which cells divide to form two identical daughter cells is called:

Find the odd one out: 3, 5, 7, 12, 17, 19

Which process increases genetic variation in populations?

Statements: All doctors are educated. Some educated are wealthy. All wealthy are successful. Some successful are happy. Conclusion I: Some doctors are happy. Conclusion II: Some educated are successful. Which is correct?