## Elementary Technical Mathematics

a) Create a proportion using ratios of lb : square foot. $\frac{25\ lb}{1200\ ft^2}=\frac{x\ lb}{3000\ ft^2}$ Set the product of the means equal to the product of the extremes and solve for the variable. $1200\times x = 25\times3000$ $1200x=75000$ $1200x\div1200=75000\div1200$ $x=62.5$ b) Create a proportion using ratios of lb : bag. $\frac{25\ lb}{1\ bag}=\frac{62.5\ lb}{x\ bag}$ Set the product of the means equal to the product of the extremes and solve for the variable. $1\times 62.5 = 25\times x$ $62.5=25x$ $62.5\div25=25\div25$ $2.5=x$ Round up to 3 bags to have enough.