Question

two tuned forks are struck at the same time. one tuned fork has a frequency of 20 hz while the second tuned fork has a frequency of 226 hz. how many beats will result?

Answer 1

226-20=??
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html

Answer 2

actually, it depends on what you mean by beats. In this case, one will hear the sum (246) and the difference frequencies (206), as well as the 226hz. Most will never hear the 20hz, but some can.
Normally, mixing near frequencies, we mean by beat the difference of the frequencies, but in reality, one gets the sum and the difference.