What is full of holes but still holds water?

How many times in a given day, minutes and hour clock comes in a straight line ?

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?

Can you count the number of triangles in the given picture?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

Replace the question mark with the correct number in the below-given picture?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?