What number when divided in half becomes zero?

What has 13 hearts but no other organs?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

An office is divided into 8 cubicles. How many of the cubicles are painted if only 1/8 of the cubicles are painted?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

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?

What can you deduce from the following BrainBat?

CRY
LMKI

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

What occurs twice in a week, once in a year but never in a day?

1. How can we put an elephant in the refrigerator?
2. How can we put a Giraffe in a refrigerator?
3. The king of the jungle invites all the animals to a party everyone comes except for one animal, which animal?
4. You come to a crocodile-infested lake, you can't go around it, you can't co under it and you can't go over it, how do you get across?