let's firstly convert the mixed fraction to improper fraction, bearing in mind that there are 16oz in 1lb, so it'll be their product.
[tex]\bf \stackrel{mixed}{5\frac{1}{8}}\implies \cfrac{5\cdot 8+1}{8}\implies \stackrel{improper}{\cfrac{41}{8}} \\\\\\ \cfrac{41}{8}\cdot \stackrel{oz}{16}\implies 41\cdot \cfrac{16}{8}\implies 41\cdot 2\implies 82[/tex]
