The centre of the third figure is empty. What digit should fit inside?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

What is the difference between a jeweller and a jailer?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

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?

Can you count the number of triangles in the picture below?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

What's the only room from which no one can enter or leave

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.