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?

Can you divide numbers from 1 to 9 (1 2 3 4 5 6 7 8 9) into two groups so that the sum of the numbers of each group is equal?

Note: 9 cannot be turned over to make it 6.

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

What is 3/7 chicken, 2/3 cat and 2/4 goat?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Keyboard words are not in alphabetical order, Why?

Once while in his court, King Akbar asked Birbal to write something on a wall that makes one sad when read in good times and makes one happy when read in sad times.

He took only a few moment and wrote something that fit the requirements. What did he write?

A frog is at the bottom of a 30-meter well. Each day he summons enough energy for one 3-meter leap up the well. Exhausted, he then hangs there for the rest of the day. At night, while he is asleep, he slips 2 meters backwards. How many days does it take him to escape from the well?

What kind of band never plays music?