What word is pronounced the same if you take away four of its five letters?

Look at the picture and find out which square is not linked with any of the other squares.

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

In the picture given below, can you find out which digit will take place of the question mark?

How can you make number one disappear by adding something to it?

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

Take one out and scratch my head, I am now black but once was red. What am I?

If an electric train is travelling south, then which way is the smoke going?