What has to be broken before you can use it?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?

A bomb exploded in a room full of married couples and no one died. How?

What does a man do only once in his lifetime, but women do once a year after they are 29?

Three logicians went to bar for having a drink. The bar person asks the logicians "Do they all want to have the drink?". The first logician replied, " I don't know". The second logician replied, " I don't know". What is the reply of the last logician?

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

Six people park their car in an underground parking of a store. The store has six floors in all. Each one of them goes to a different floor. Simon stays in the lift for the longest. Sia gets out before Peter but after Tracy. The first one to get out is Harold. Debra leaves after Tracy who gets out on the third floor.

Can you find out who leaves the lift on which floor?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

I drive at an average speed of 30 miles per hour to the railroad station each morning and catch my train. On a particular morning, there was a lot of traffic and at the halfway point, I had averaged only 15 miles per hour. How fast must I drive for the rest of the way to catch my train?