Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

What is black when you buy it, red when you use it, and gray when you throw it away?

A time long back, there lived a king who ruled the great kingdom of Trojan House. As a part of the renovation of the kingdom to meet future security needs, he asked his chief architect to lay down a new play in a manner that all of his 10 castles are connected through five straight walls and each wall must connect four castles together. He also asked the architect that at least one of his castles should be protected with walls. The architect could not come up with any solution that served all of King's choices, but he suggested the best plan that you can see in the picture below. Can you find a better solution to serve the king's demand?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

I look at you, you look at me, I raise my right, you raise your left. What am I?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

You are an expert on paranormal activity and have been hired to locate a spirit haunting an old resort hotel. Strong signs indicate that the spirit lies behind one of four doors. The inscriptions on each door read as follows:

Door A: It's behind B or C
Door B: Its behind A or D
Door C: It's in here
Door D: It's not in here

Your psychic powers have told you three of the inscriptions are false, and one is true. Behind which door will you find the spirit?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?