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?

If 21x = 79x, what is the value of x?

Count the number of squares in the picture below.

Which letter of the alphabet has the most water?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

What you cannot hold but it is yours?

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

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.