Can it be possible to build a house that has all its four walls facing towards the South?

Can you find out the number that should replace the question mark with a valid reason?

What is next number in the pattern below:

131 517 192 123 ?

Given below is simple addition with a defined pattern pattern:
7 + 7 = 2
8 + 8 = 4
8 + 5 = 1
6 + 9 = 3
10 + 11 = 9

Can you analyze the pattern and find out the answer for:

4 + 9 = ?

Something Extraordinary happened on May 6th 19778 at 12:34am what was that?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

What's a single-digit number with no value?

Where do fish keep their money?