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

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

You have three orange, two pink and five purple balls in the drawer beside your bed. There is no electricity and the room is entirely dark. How many balls must you take out to ensure at least one ball of each colour at least?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

John leaves home and then he takes three right turns. John wants to return to home but he was scared of Jacob, who is wearing a mask.

What is John Situation ?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

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

Can you solve the below algebraic mathematical equation?

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

Katniss and Peeta are liars. They both lie on some specific days.

Katniss lies on Fridays, Saturdays and Sundays. She speaks the truth on all other days.

Peeta lies on Tuesdays, Wednesdays and Thursdays. He speaks the truth on all other days.

Can you tell that one day of the week when both of them will say "Tomorrow, I will lie."?