Can you place six X (crosses) in below board without making three in a row in any way ?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

I add 5 to 9 and get 2. The answer is correct, so what am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

What is 3/7 chicken, 2/3 cat and 2/4 goat?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

what's the probability of getting a king or a queen from a pack of 52 cards?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Why do people go to bed?

In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?