10+10 and 11+11 can give you the same answer.

Explain how?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

I am quite hot but become too cold if you remove the first two letters. What am I?

There is a number which when you multiply by 3 and subtract 2 from the result, then the resulting number is the reverse of the actual number.

What is the smallest number that stands true on the statement?

A woman named Maria was at the funeral of her mother. She met a nice young man that she had never seen before and after the service, they spent a bit of time together. Then she got busy and didn’t get his name or phone number before he left. She tried to find him, but no one knew who he was or how to contact him. A few weeks later, Maria’s older sister dies and the police suspect murder. Who killed the sister?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

What is the last thing you take off before bed?