Find each unit price. Which is the better buy? Explain Electrical wire : $1.49 for 3 ft or $.69 for 18 in. Explain

This will depend on several factors. The two most important are gauge of wire and the current you are running through it. A heavier gauge wire can hold more current safely but might be too heavy for your needs.

If they are the same gauge then cost per foot is the only factor then $.69 for 18 inches is the better deal because 3 ft will be $1.38

Here unit price = price / length

$1.49 / 3 = $0.50 / ft

$0.69 / 1.5 = $0.46 / ft