I have eight fingers and two thumbs but I do not live. What Am I?

Pronounced as 1 letter, And written with 3, 2 letters there are, and 2 only in me. I’m double, I’m single, I’m black blue and grey, I’m read from both ends, and the same either way. What am I?

Rearrange the letters in "new door" to make one word.

How can you drop a raw egg from a height onto a concrete floor without cracking it?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Can you start the fire using two pieces of wood?

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

Can you find the thief by just looking at the picture below?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

Can you find the key in the picture below?