In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

Can you find out the total number of triangles in the given figure?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

What is full of holes but still holds water?