What has many keys but can’t open a single lock?

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

Prove that twice of ten is the same as twice of eleven.

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

Where do fish keep their money?

Aaron, Brad, Christopher, Danny and Elvis decided to play a game of tiddlywinks. In this game they decided that one win will get 1 point for winning, 0 for losing and 1/2 in case of a tie.

They finished the game in alphabetical order and it was found that the scores were different for each person.

Based on the following two statements, can you find out the result of the individual games?
Brad: No one could finish like me, without a loss.
Elvis: No one played worse than me, I finished without a single win.

Replace all '*' with digits 1, 2, 3, 4, 5 and 6 to make below statement true.

* *
x *
=====
* * *

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

What's the only room from which no one can enter or leave