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

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

John is a strange liar.

He lies on six days of the week, but on the seventh day, he always tells the truth.

He made the following statements on three successive days:

Day 1: "I lie on Monday and Tuesday."
Day 2: "Today, it"s Thursday, Saturday, or Sunday."
Day 3: "I lie on Wednesday and Friday."

On which day does John tell the truth?

Replace the question mark in the picture below.

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

Can you find the missing piece of the Porsche?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Use the numbers 2, 3, 4 and 5 and the symbols + and = to make a true equation. Conditions: Each must be used exactly once and no other numbers or symbols can be used.

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.