What runs around the whole yard without moving?

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

Our product and our sum always give the same answer. Who are we?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

Can you find a rabbit in the given picture?

What do you answer even though it never asks you questions?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

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 ?

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?