Why 1729 is a magic number? Answer Logically.

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

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

Can you count the number of triangles in the picture below?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

Replace the question mark in the picture below.