how many vibrations will a tuning fork of frequency 280 hz will complete during the time sound travels forward in air by 18 cm.speed of sound in air be 336 m/sec

Given,
Speed of sound=336 m/s
Distance=18 cm=0.18 m
Time=Distance / Speed=0.18/336=5.4 s
Since, frequency=280 Hz
i.e number of vibrations completed in one second=280
Thus, the number of vibrations completed in 5.4 s=280 x 5.4=1512