Why is 6 afraid of 7?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

What is the relationship between these matchstick pictures below?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

What kind of storm is always in a rush?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

From a pack of 52 cards, I placed 4 cards on the table.

I will give you 4 clues about the cards:

Clue 1: Card on left cannot be greater than the card on the right.
Clue 2: Difference between the 1st card and 3rd card is 8.
Clue 3: There is no card of an ace.
Clue 4: There are no face cards (queen, king, jacks).
Clue 5: Difference between the 2nd card and 4th card is 7.

Identify four cards?

In a certain bank, a man deposits a certain amount. According to the bank policies, the amount will be doubled up in a year but as the service charge, they will also deduct Rs. 65 by the end of every year.

If after the 6th year, the amount becomes 0, what do you think is the original amount he deposited in the bank?

Move four matchsticks to the below square to form three squares?