64 tuning forks are arranged in order of increasing frequency. The frequency of the last fork is double of the first and each two consecutive forks produce 4 beats per second. Calculate the frequency of the last fork.

Explanation

Let frequency of 1st fork `=n`
frequency of 2nd fork `=n+4=n+4(2-1)`
`:.` frequency of 64th fork `=n+4(64-1)=2n or n=252Hz.`
Frequency of last fork `=2n=2xx252=504Hz`