221 is rational since 221 = 221/1
So is 331 because 331 = 331/1
The product of any two rational numbers is also rational
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Proof:
Let x = p/q and y = r/s be two rational numbers. The q and s values are nonzero.
Their product is
x*y = (p/q)*(r/s)
x*y = (p*q)/(r*s)
which is a ratio of two integers pq and rs, so (p*q)/(r*s) is rational
