Which number should replace the question mark?

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?

Sharpest vision can find the lamp in the desert. Are you one of them? Test your observation skills now!

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

Which organisation is a specialized agency of the UN that deals with global health issues?

a) World Trade Organization (WTO)
b) World Health Organization (WHO)
c) International Monetary Fund (IMF)
d) United Nations Educational, Scientific and Cultural Organization (UNESCO)

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

Can you replace the question mark with the correct number in the below table sequence?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?