Which Number is the odd one out?

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

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?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

It is always ahead of me yet I can never see it. What is it?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

I’m tall when I’m young, and I’m short when I’m old. What am I?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Find the missing number in the sequence below:

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?

John needs to purchase 100 chocolates from three different shops and he has exactly 100 rupees to do that which he must spend entirely. He must buy at least 1 Chocolate from each shop.

The first shop is selling each chocolate at 5 paise, the second is selling at 1 rupee and the third is selling at 5 rupees.

How many chocolates should he buy from each shop?