Which number should replace the question mark?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

How many bananas can you eat if your stomach is empty?

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

Why Aeroplane windows are round?

You’re out on the water and see a boat filled with people. You look away for a second and look back again, but this time you don’t see a single person on the boat. Why? Hint: The boat did not sink.

Find the next number in the following series:
6, 14, 26, 98, __?

Why is the Hole below a Lock?