What is the name of this book?: The riddle of Dracula and other logical puzzles

This is a book that parents should buy for their adolescent children (until it becomes compulsory reading at school). It provides both the entertainment of tales and the much needed ability to reason.
Solving the riddles set forth by the author is one of the best investment of their time the readers can do. It will repay many times whatever line of work they end up embarking on. It is also fun.