What is both possible and impossible at the same time?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

What is the longest word in the dictionary?

Take away the whole and some still remain. What is it?

I cannot talk, but I always reply when spoken to. What am I?

Count the number of triangles in the picture below:

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?

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