If 7@8 = 15, 3@5 = 8, 9@2 = 11, then 4@6 = ?

If 5#3 = 34, 7#4 = 65, 2#6 = 40, then 8#5 = ?

Five people A, B, C, D, E sit in a row facing north. A sits at one end. B sits next to A. C does not sit next to B. D sits between C and E. Who sits at the other end?

Enzymes are biological catalysts made of:

Statements: Some questions are easy. Some easy are solved. All solved are correct. Some correct are verified. Conclusion: Some questions are verified. Is this valid?

Statements: All roses are flowers. Some flowers are thorns. No thorn is a leaf. Some leaves are stems. Conclusion I: Some roses are thorns. Conclusion II: No flower is a stem. Which is correct?