Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

I start and end with 500 and carry a 5 in my heart. But I require the first letter and the first number to be complete. I am the name of a King.

Who am I ?

What always comes into a house through the keyhole?

What does below pictogram mean?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

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

How Come ??

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

These types of puzzles are known as charades. What you have to do is to 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 the '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.

When monkey rotate the gear, which mark will be hit 1 or 2 ?