Which of the following could be the fundamental freq. for a vibration that has an overtone freq. of 990 Hz? a. 330 b. 660 c. 148 d. 1980 e. 1990 (All in Hz.) The formula that I think you have to use is f_n = n*f_1, where f_1 is fud. freq. Then, I thought f_2 = 2*f_1, where f_2 is the overtone freq. (is these a correct assumption?) but 990/2 is 495. Could someone direct me to the correct path of getting the solution? I'm confused over the definitions of overtone and fund. freq. Thanks.