Answer
Find out the Philip error.
To prove
As given
A two pound box of spaghetti costs $2.50.
[tex]Philip\ says\ that\ the\ unit\ cost\ is\ \frac{2}{2.50} is\ equal\ 0.80\ dollar\ per\ pound.[/tex]
Philip calculated the unit cost by wrong method he divided weight by the cost which is wrong.
2 pound box of spaghetti costs = $2.50
[tex]one\ costs\ of\ box = \frac{Total\ cost\ of\ two\ pound\ cost}{Total\ pounds}[/tex]
[tex]unit\ cost\ of\ box = \frac{2.50}{2}[/tex]
unit cost of box = $1.25
Therefore the unit cost of box is $1.25 .