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?

If eleven plus two equals one, what does nine plus five equal?

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

One day, John and his friends were playing around. Jacob hit something with a Pin and it popped. John's dad came into the room that very moment, but he wasn't mad. In fact, he was smiling. What did Jacob hit?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

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