What does this simple rebus mean?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

It is always ahead of me yet I can never see it. What is it?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

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

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?

I have branches, but no fruit, trunk or leaves. What am I?