It belongs to you, but other people use it more than you do. What is it?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

Mr Red Lives in the red house.
Mr Green Lives in the greenhouse.
Mr Yellow Lives in the yellow house.

Who lives in the Whitehouse?

Detective Rockford was jogging near the beach at 4:30 am.
He hears a sound near the shack "No Michael, Please Do not shoot me".
Next instance he heard the sound of gunfire. Rockford rushes to the shack where he finds women lying dead and a gun in close proximity of three "Doctore Lawyer and a Teacher".

Rockford immediately knew that the Lawyer has committed the crime. How?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Why do you find that most of the buildings are deprived of the 13th floor?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

What does below Rebus mean ?

esgg sgeg gegs gsge

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?