A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

Can you identify if it's a murder or a suicide ?

It is always ahead of me yet I can never see it. What is it?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

You need to arrange three 7 and mathematical symbols to form number 1?

What is the next number in this matchsticks series riddle?

Why do people go to bed?

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

What is the last thing you take off before bed?

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()