Question

Johnny Can Buy two 8-foot pieces of 2" by 4" lumber at $2.60 each, or three 6-foot pieces for $1.92 each. Which is the better buy per foot?

Answer 1

Set them up as a proportion to find the unit cost for each foot.

$\frac{2.6}{8} = \frac{x}{1}$

$\frac{1.92}{6} = \frac{x}{1}$

Divide 2.6 by 8.

2.6/8 = 0.325

Divide 1.92 by 6.

1.92/6 = 0.32.

Three 6-foot pieces are better by 0.005.