Name a key which is hardest to turn.

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Chhote se Chintu Miyan,
Lambi si Pooch.
Jahan Jaye Chintu Miyan,
Wahan Jaye Pooch.

छोटे से चींटू मियाँ,
लंबी सी पूंछ।
जहाँ जाये चींटू मियाँ,
वहाँ जाये पूंछ।

Bolo kya?

Can you solve below mathematical equation?

2^1234 - 2^1233

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

Take away the whole and some still remain. What is it?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Can you find out the total number of triangles in the given figure?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?