If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

What can you see in the middle of March and April that you can never see in any other month?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Find the last number in the series below:

voN luJ yaM raM ---

Evil warlock dislikes dwarfs and therefore he selects four of them and buries them. The dwarfs are buried in the ground and they are in such a way that except for their heads, their body is inside the ground. The dwarfs cannot move their body and they can view only forward. They are all buried in a line, and amongst the four, one of the dwarfs is separated by a wall. All the dwarfs are in the same direction. The last dwarfs can see two heads of friends in the front and a wall. In the last second dwarf can see one head of his friend and a wall. The second dwarf can see only the wall. The dwarf can see nothing.
Warlock comprehends the situation and tells the dwarfs that he has placed hats on their heads. There are two blue hats and two red ones. In all four dwarfs, one of them has to say what colour hat he is wearing. If the dwarf says the correct colour of the hat, they will be left free. If the answer is wrong, then they will be dug inside the ground till the very end.

What will be the answer by the dwarf and how will they answer?

How could a baby fall out of a twenty-story building onto the ground and live?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?