13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Can you count the number of blocks in the picture below?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

What time is it when an elephant sits on a fence?

There are two beautiful yet remote islands in the South Pacific. The Islanders born on one island always tell the truth, and the Islanders from the other island always lie.
You are on one of the islands and meet three Islanders. You ask the first which island they are from in the most appropriate Polynesian tongue, and he indicates that the other two Islanders are from the same island. You ask the second Islander the same question, and he also indicates that the other two Islanders are from the same island.
Can you guess what the third Islander will answer to the same question?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

You can see three almost identical images below. Can you spot the odd one out from them?

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