A 2-pound box of speghetti costs 2.50. Phillip says that the unit cost is 2/2.50=0.80 per pound

1. There’s 2 pound box of spaghetti costs 2.50

Philip Unit costs = 2 / 2.50 =.80 per pound.

Which is wrong because 0.80 x 2 = 1.60 only, so the method that Philip followed is not right,

This is how you get the Unit cost, use this formula

=> Since there are 2 pounds of spaghetti and the price is 2.50

=> 2.50 costs / 2 pounds

=> 1.25/pound

thus, the spaghetti costs 1.25 dollars per pound