Can you name some countries which do not have the alphabet 'A' in them?

I travel all around the world but always stay in the corner. What am I?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

What is more useful when it is broken?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

You are a cab driver who pools passengers. You pick 3 people from a destination and drop 1 after an hour. 2 people climb aboard at the same time and you drop 3 at the next destination. After some time, you pick 2 passengers only to drop 1 after a short distance where 3 more passengers climb up the cab. You leave the rest of the passengers one by one to their destination and then come back home.

Can you tell the eye color of the cab driver?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Can you find out the remainder when 3^300 is divided by 5?