Spot 5 differences in two Christmas tree below:

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

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

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

what does the below rebus means?

What is the relationship between these matchstick pictures below?

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

Can you find the hidden animal in the picture below?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?