By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

Make a sentence consisting of three words that have the whole alphabet.

Find out the missing number in the picture attached:

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?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

Before Mount Everest was discovered, what was the highest mountain in the world?