The centre of the third figure is empty. What digit should fit inside?

Two natural numbers have a sum of less than 100 and are greater than one.

John knows the product of the numbers and Jacob knows the sum of numbers.

The following conversation takes place between them:
John: 'I am not aware of those numbers.'
Jacob: 'I knew you wouldn't be. I am not aware myself.'
John: 'Now I know them!'
Jacob: 'Now I know them, too!'

What are the two numbers?

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

A father's child, a mother's child, yet no one's son.

Who am I?

Which digit occurred maximum times between the number 1 and 1000?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

I guess 76.8% of readers will like this riddle.

What's the least number of people should read this post?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

What question can you never answer yes to?