What English word has three consecutive double letters?

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)

Find the next number in the series below

21 32 54 87 131 ?

You can see three almost identical images below. Can you spot the odd one out from them?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

Why do you find that most of the buildings are deprived of the 13th floor?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

I am sure no one can have two things for dinner. what are they?