- Do you know which ball will finish first? Or can you determine the inside of a sphere without tools? Or explain what will happen to the inner diameter of a washer when heating it? The explanations to these riddles seem complex but are straightforward when using your creativity and lateral thinking. In this book, 'Technical riddles', a collection of 40 technical riddles are explained in detail with many providing hyperlinks to resources for even more information related to the subject. Technical riddles are commonly used in job interviews in the engineering sector. This book will help you to create your own technical riddles.