In the four images below, can you find the odd one out?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Can you solve the photo plexer logic ?

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?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

What does this rebus mean?

O
N
C
E
TIME

Find the next number in the series below

21 32 54 87 131 ?