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.

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

When is the top of a mountain similar to a savings account?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

How many triangles can you find in this given picture?

John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3

If you had an infinite supply of water and 5-quart and 3-quart pails, how would you measure exactly 4 quarts? What is the least number of steps you need?