When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

What does this Rebus Picture mean?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

Can you write down eight eights so that they add up to one thousand?

Find the next number in the series below

21 32 54 87 131 ?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Why do we preferably have round manhole covers and not square ones?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

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?

how come the second man dies?