There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

How many sides does a circle have?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

A river should be crossed by a father, a mother and their two sons and two daughters.
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.

How will they cross the river?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

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?