Three musical notes with frequencies 300 Hz, 400 Hz, and 500 Hz are sounded simultaneously. At which of the following years will the combined sound frequencies be heard simultaneously again?

100, 200, 300, 400, 500 years

100, 200, 400, 500 years

200, 300, 400, 500 years

100, 200, 300, 400 years

Explanation

What happens: Sounds repeat their cycles over time.

Key idea: Find the common multiples of the frequencies (or periods).

Frequencies heard at: Years that are multiples of the Least Common Multiple (LCM) of 300, 400, and 500, which relates to the years 100, 200, 300, 400, 500 (all multiples of 100).