Two of the three tuning forks have known frequencies. When a 610 Hz fork and the unknown fork are struck together, four beats per second are heard. When a 605 Hz fork is struck with the unknown fork, beats are produced that are too numerous to count accurately. What is the frequency of the unknown fork?

614

606

I'm sorry i thought i put 614 Hz i guess i didn't

i ment to say 614 Hz

- - In combination with 610 Hz, the beat frequency is 4 Hz.

So the unknown frequency is either (610+4) = 614 Hz

or else (610-4) = 606 Hz.

In combination with 605 Hz, the beat frequency will be

either (614-605) = 9 Hz or else (606-605) = 1 Hz.

- - In actuality, when combined with the 605 Hz, the beat

frequency is too high to count accurately. That must be

the 9 Hz rather than the 1 Hz.

So the unknown is (605+9) = 614 Hz.