One pipe has successive harmonics of 165 Hz, 275 Hz, and 385 Hz, and another pipe has successive harmonics of 165 Hz, 220 Hz, and 275 Hz. (a) Which pipe is closed at one end and which is open at both ends

165 Hz, 220 Hz, and 275 Hz belongs to pipe open at both ends

165 Hz, 275 Hz, and 385 Hz belongs to pipe closed at one end

Explanation:

Open ended pips have harmonic frequencies that are multiple of the fundamental frequency

Find the fundamental frequency for each of the samples:

165Hz, 275Hz, 385Hz

(275-165) = 110

(385-275) = 110

165 Hz, 220 Hz, and 275 Hz

(220-165) = 55

(275-220) = 55

F = 55

Note that 165 = 3f

220=4f

275=5f

SO these frequencies are multiples of the fundamental frequency