Hey, I just signed up and I've already got a question. =) The answer was in the book but I don't get the answer. Determie the frequency of a spark timer set at a period of 0.10s. Ans: 1.0 x 10¹ Hz. The book only says; The answer is literally staring me right in the face and the explanation might be really easy but for it's just not making sense to me. Can anyone help? Thanks a lot!