What has 13 hearts but no other organs?

Find the hidden tiger in the given optical illusion ?

I am white when I am dirty, and black when I am clean. What am I?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

Spot what is wrong here in below Picture?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

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

No matter how little or how much you use me, you change me every month. What am I?