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

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

If Bihan is 10, Anirudha is 20, and Kim and Seal are both 5, but Rikold is 10, how much is Kenniger by the same trend?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

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

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

what's the probability of getting a king or a queen from a pack of 52 cards?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?