How many times can you subtract the number 5 from 25?
It's a test that will check your IQ. Suppose you have one 11 minute hourglass and one 13 minute hourglass. Can you measure exactly fifteen minutes using them ?
There are 2 sand hourglasses. The small one can measure 5 hours and the large one can measure 7 hours. How can we measure 16 hours with 2 sand hourglasses running together ?
Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?
Why is it very easy to weigh a fish?
Can you spot the man between the coffee bean in the picture below ?
Use the numbers 2, 3, 4 and 5 and the symbols + and = to make a true equation. Conditions: Each must be used exactly once and no other numbers or symbols can be used.
What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?
Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?
Can you find the missing letter in the sequence? S - T - I - L - ? - T - F - Y - C
Which tank will fill first?
In the 1920s, people feared that crossword puzzles would contribute to illiteracy.