Give me food, and I will live; give me water, and I will die. What am I?

There is an ancient invention still used today in some parts of the world which allows people to see through walls. What is it?

A cow is tied to a 4 meter long rope. There is food, 20 meters away from the cow. However, the cow manages to go to the food and eat it. How come?

I have keys without key locks.I have space without rooms.You can enter but you cannot go outside.

When you have me, you immediately feel like sharing me. But, if you do share me, you do not have me.

What is correct to say – “the yolk of the egg is white” or “the yolk of the egg are white”?

What number comes next in the following sequence? 2 4 8 10 20 __

When can you add two to eleven and get one as the correct answer?

A boy is walking down the road with 3 people in his family. One of them is a doctor. While the boy is the doctor’s son, the doctor is not the boy’s father. Then who is the doctor?

While going to the fair, John met 5 clowns on his way. Each clown had 4 dogs, each dog had 2 cats and each cat had 2 mice. How many in total were going to the fair?

What 5-letter word becomes shorter when you add two letters to it?

A bat and a ball cost €1.10. The bat costs one euro more than the ball. How much does the ball cost?