Can you find the odd number in the following?

2716, 4135, 5321 and 7145

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

I ask Joseph to pick any 5 cards out of a deck with no Jokers.

He can inspect then shuffle the deck before picking any five cards. He picks out 5 cards then hands them to me (Jack can't see any of this). I look at the cards and I pick 1 card out and give it back to Joseph. I then arrange the other four cards in a special way, and give those 4 cards all face down, and in a neat pile, to Jack.

Jack looks at the 4 cards i gave him, and says out loud which card Joseph is holding (suit and number). How?

The solution uses pure logic, not sleight of hand. All Jack needs to know is the order of the cards and what is on their face, nothing more.

A bus driver was heading down a street in Mexico. He went right past a stop sign without stopping, he turned left where there was a "no left turn" sign, and he went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Still - he didn't break any traffic laws. Why not?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

How can a man go eight days without sleep?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

What is the largest number you can write with just 3 digits?