Which number should replace the question mark?

Can you make a six-letter word using the letters N, A and B ?

Our product and our sum always give the same answer. Who are we?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

You are a cab driver who pools passengers. You pick 3 people from a destination and drop 1 after an hour. 2 people climb aboard at the same time and you drop 3 at the next destination. After some time, you pick 2 passengers only to drop 1 after a short distance where 3 more passengers climb up the cab. You leave the rest of the passengers one by one to their destination and then come back home.

Can you tell the eye color of the cab driver?

What word begins and ends with an E, but has only one letter?

Why Aeroplane windows are round?

How can you tell a raw egg from a hard-boiled egg?

If 21x = 79x, what is the value of x?

The two towns are exactly 100 km apart. John leaves City A driving at 30 km/hr and Jacob leaves City B half an hour later driving at 60 km/hr. Who will be closer to City A when they meet?