They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

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

Which tank will fill first?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What is the fastest way to double your money?

In which direction should the missing arrow point?

You have a thousand Re. 1 coins with you. You have ten bags with you and you can put any number of coins in each of the bags. The condition is that if someone asks you for any amount between 1 and 1000, you must be able to give that amount by just giving the bag (you are not allowed to open the bag and give coins).

How will you do it?

John is found dead in his office at his desk. The police have narrowed the suspects down to three people: Mrs. Jacob, John’s wife Hena and his business partner Jason . All three visited John on the day of his murder, but all three provide the police with stories of explanation as to the reason for their visit.
Police found John with his wrist watch still on his right arm, a torn up picture of his wife laying on the floor beside the trash can, and an ink pen in his right hand. On the desk, the police found a name plate, a telephone that was off the hook, and a personal calendar turned to the July 5th page with 7B91011 written on it. After examining this evidence, the police knew their suspect. Who was it ?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?