I look at you, you look at me, I raise my right, you raise your left. What am I?

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?

Can you count the number of squares in the given picture?

What occurs twice in a week, once in a year but never in a day?

what's the probability of getting a king or a queen from a pack of 52 cards?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Which number comes next in the number series?

2, 9, 30, 93, ?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?