Can you make four (4) nines (9) equal 100?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

There is something which is always coming but never arrives?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

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?

Can you name some countries which do not have the alphabet 'A' in them?

Solve this riddle by finding the odd one out from the rest.