Name a key which is hardest to turn.

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

Replace the question mark in the picture below.

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

In the following picture, E is going to slide the object down and as per the terrain and the physics, the round object is going to travel all the way till the end. Now, can you analyze who all people will die when it happens?

What is the word or phrase?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.