Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

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?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

At Delhi Cricket Clubhouse, there were four kids(Kohli, Yuvraj, Pant, and Dhoni) ages 1,2,3 and 4 and have 1,2,3 and 4 cricket balls in different orders.

We know the following facts:

Kohli has more cricket balls than his age.
Dhoni is older than Yuvraj.
One child has the same number of cricket balls as his age.
Pant has fewer cricket balls than Dhoni.
A child aged 3 has two cricket-balls.

Pant is the youngest.

Can you determine the age of the children and the number of cricket balls they have?

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?

Which number should replace the question mark?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?