What does below rebus means ?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

Bopanna was working on a murder case when he received a message about the location of the murder weapon.
The message was encrypted as below.

"deb mitciv eht edisni neddih si nopaew redrum ehT"

Tell me the location of the murder weapon.

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

Name a key which is hardest to turn.

What is both possible and impossible at the same time?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

A cat, a dog and a monkey were stolen. 3 suspects got caught: Harish, Manoj and Tarun. All we know is each person stole one animal, but we do not know who stole which. Here are the investigation statements. Harish said: Tarun stole the cat. Manoj said: Tarun stole the dog. Tarun said: They both were lying. I did not steal the cat or the dog. Later on, the police found out the man who stole the monkey told a lie. The man who stole the cat told the truth. Can you find out who stole which?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?