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

Which alphabet letter is a question?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

Can you find a five letter word that is left with only two letters if one is removed?

To attend world science seminar, A famous chemist from Mexico visit
London. In the lab, the scientist was killed and his six assistants were under suspicion of killing the chemist.
Name of six assistants: Austin, Wayne, Dege, Oscaru, Lingard, and Rojo.
He left a note "76-20-44 79-16-22-7"

A local detective Jack was called to solve the case,

After reading the note, Jack instantly asked the police to arrest the murderers.

Who are the murderers?

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

I travel all around the world but always stay in the corner. What am I?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

Can you start the fire using two pieces of wood?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?