Because
Problem
yes it is a mystery book ! i had the same problem when i was a kid :)
In "Sammy Keyes and the Night of Skulls," the main problem revolves around Sammy investigating a mystery involving a missing girl in her town while also dealing with personal challenges and navigating her relationships with friends and family. The story highlights themes of friendship, loyalty, and determination as Sammy works to solve the mystery.
A problem is any thing, any matter or any person that is difficult to deal with, although there is expected to be a solution. A mystery is anything that is kept secret or unexplained
Conundrum, enigma, riddle, mystery, problem...
it was a mystery
an educated guess about a possible solution to a mystery or problem is a theory.>>> hope this helps .
mystery
"Farewell, My laura"
Mystery Diners - 2011 All in the Family 3-5 was released on: USA: 17 May 2013
The Berenstain Bears - 2002 Family Get-Together The Stinky Milk Mystery was released on: USA: 2003
A non-example of a mystery is a straightforward math problem, such as "What is 2 + 2?" where the answer is clear and easily determined. Unlike a mystery, which involves uncertainty or requires investigation to uncover hidden information, this math problem has a definite solution that does not require any additional context or exploration.