What has many keys but can’t open a single lock?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

Find the last number in the series below:

voN luJ yaM raM ---

My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

What is both possible and impossible at the same time?

I am the fastest animal but cannot climb the tree. What am I?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

Replace the question mark with the correct number in below Picture: