Engineering Economics Example1

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Ok, here's my first Engineering Economics Example(using Newnan, Eschenbach, and Lavelle) as the resource.

A construction aggregate mixture of a substance needs to contain at least 33% of a substance we shall call material A by volume to be correct. A certain source material has 27% material A and 73% course aggregate sells for $5.00 per cubic meter (m^3). Another source which has 42% material A and 58% course aggregate material sells for $8.6 per cubic meter. Determine the least cost per cubic meter of blended aggregates.

Let x = portion of blended aggregates $5.00 / m^3 source

Let 1-x = portion of blended aggregate from $8.60 / m^3 source

continuing below:

material A balance equation:

x(0.27) + (1-x)(0.42) = 0.33 and solving for x = 0.6

As can be seen the blended aggregates contain 60% of the $5.00 / m^3 material

and 40% of $8.60 / m^3 material

The least cost per cubic meter of blended aggregates is:

0.6($5.00) + 0.4($8.60) = $6.44 / m^3

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