Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

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A sundial has the fewest moving parts of any timepiece. Which has the most?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Find the next number in the sequence

5 12 24 36 ?

Spot what is wrong here in below Picture?

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Who can jump higher than a Mountain?

Find the missing number in the image below.