Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Which tank will fill first?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

What does man love more than life, and hate more than death or mortal strife; that which satisfied men want; the poor have, and the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?

Here is a Swiss Cross. You have to make two straight cuts in the figure so that it is divided into four congruent pieces. Also, you should be able to join these pieces into a square then. Can you accept this challenge?

If six children and two dogs were under an umbrella, how come none of them got wet?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

Why is a river so rich ?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?