Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Which tank will fill first?

I am a five-letter word and people eat me. If you remove the first letter I become an energy form. If you remove the first two letters, I am needed to live. Scramble the last three letters and I am a drink. What word am I?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)

What jumps when it walks and sits when it stands?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?