Why Aeroplane windows are round?

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

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

What is the longest word in the dictionary?

Replace the question mark with the correct number in the below-given picture?

Complete the given grid with valid words. You can only use the letters AAEEIIMMPPTT.

Hint: The grid reads the same across as down.

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Can you solve the below tricky visual equation?

When we see 2 but call 10?

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?