If eleven plus two equals one, what does nine plus five equal?

Take one out and scratch my head, I am now black but once was red. What am I?

Six people park their car in an underground parking of a store. The store has six floors in all. Each one of them goes to a different floor. Simon stays in the lift for the longest. Sia gets out before Peter but after Tracy. The first one to get out is Harold. Debra leaves after Tracy who gets out on the third floor.

Can you find out who leaves the lift on which floor?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

The picture shows the dice results in each couple of throws. If they are actually following a pattern, can you find out the missing one?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Forwards I am heavy, backward I am not. What am I?

I throw two dice simultaneously.

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