There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

What does this mathematical rebus means ?

A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

A hen, a dog, and a cat are stolen. Three suspects are arrested named Robin, Steve, and Tim. The police are sure that all of them stole one of the animals but they don't know who stole which animal.

Sherlock Holmes is appointed to identify and is provided with the following statements from the investigation.

Robin - Tim stole the hen
Steve - Tim stole the dog
Tim - Both Robin and Steve are lying. I neither stole a hen nor a dog.

Sherlock is somehow able to deduce that the man who stole the cat is telling a lie and the man who stole the hen is telling truth.

Can you help him find out who stole which animal?

I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.