There are three houses in a straight row. One is red, one is blue, and one is white. The red house is left of the middle. The blue house is right of the middle. Where's the white house?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

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

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

A man is surviving on an island along with his friend. They have been starving for four days for food. Suddenly, they find a fisherman. The friend goes with the fisherman in order to catch the fish (if they can find any).

The fisherman returns after some time but he is alone and has some salmon that he had prepared. When asked, the fisherman tells him that his best friend fell off the boat and drowned in the water. Starving for so long, he eats the meal while crying for his friend.

After being rescued, he goes to a diner and orders salmon. When he eats his meal, he jumps and commits suicide. Why did he do it?