Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

Which is heavier: a ton of bricks or a ton of feathers?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

If 21x = 79x, what is the value of x?

What is the next number in this matchsticks series riddle?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

Sherlock breaks into a crime scene. The victim is the owner who is slumped dead on a chair and have a bullet hole in his head. A gun lies on the floor and a cassette recorder is found on the table. On pressing the play button, Sherlock hears the message 'I have committed sins in my life and now I offer my soul to the great Lord' and followed a gunshot Sherlock smiles and informed the police that's its a murder.

Why did he think so?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

Find the next number in the series below

21 32 54 87 131 ?