What Deficiency does the below rebus represent?

VIT_MIN

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Replace the question mark with the correct number.

What English word has three consecutive double letters?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

The chance of Mr John winning the lottery is 10%. All participants lined up and Mr John is 4th in the row. The first three participants lose the lottery.

What is the chance of Mr John now?