To convert pound to kilogram you have to do as follows:
1 pound equals to 0.45 kilograms
Using cross multiplication you can determine how many kilograms are equivalent to 160pounds:
[tex]\begin{gathered} \frac{0.45}{1}=\frac{x}{160} \\ 0.45\cdot160=x \\ x=72 \end{gathered}[/tex]160pounds are equal to 72 kilograms