if each board is going to be 47 and 1/2 inches long, and there'll be 24 of them, then their total is just their product.
keep in mind that there are 12 inches in 1 foot.
[tex]\bf 24\cdot 47\frac{1}{2}\implies 24\cdot \cfrac{47\cdot 2+1}{2}\implies 24\cdot \cfrac{95}{2}\implies \cfrac{24}{1}\cdot \cfrac{95}{2}\implies \cfrac{2280}{2}
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\stackrel{inches}{1140}\implies 1140~\underline{in}\cdot \cfrac{ft}{12~\underline{in}}\implies \cfrac{1140~ft}{12}\implies 95~ft[/tex]
