That is false since product of 2 mixed numbers can be a whole number if in the product, product of denominators is a factor of product of numerators.
For example let us take [tex]1\frac{13}{25} and 6\frac{11}{19}[/tex]
[tex]1\frac{13}{25} = \frac{38}{25} and 6\frac{11}{19} = \frac{125}{19}[/tex]
So, [tex]\frac{38}{25} * \frac{125}{19} = 10[/tex]
Hence product of two mixed numbers can be a whole number,
