There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

Solve the following series:
AZ, GT, MN, __, YB

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

I am the fastest animal but cannot climb the tree. What am I?

Doctor Alex and a bus driver John are both in love with the same woman named Olivia. The bus driver need to go for a long trip of 10 days, Before he left he gave Olivia 10 apples.

A father is locked up in jail. His wife has gone bankrupt. Their male child has to sell his hotel in order to gain some money. Yet their girl child does not care and is quite happy.

How can someone be so rude?

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