There is one four-digit whole number n, such that the last four digits of n2 are the original number n

In the picture below can you find the correct switch that will turn on the bulb?

What do you see here? Your task is to find three words hidden in the optical illusion

Spot what is wrong here in below Picture?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

Can you decipher the below rebus?

PBLUESAISNUERSES

What is the unique property of the following words ?
* Revive
* Banana
* Grammar
* Voodoo
* Assess
* Potato
* Dresser
* Uneven

These types of puzzles are known as charades. What you have to do is find two words that are referred to in the first stanza and the second stanza and put them together to form the third word in the third stanza.

Just for example, if my first refers to 'off' and my second refers to 'ice', then my whole will be office.

My first is present - future's past -
A time in which your lot is cast.

My second is my first of space
Defining people's present place.

My whole describes a lack of site -
A place without length, breadth, or height.

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?