Answer: The first box (the 450 g box for $4.69)
===========================================================
Explanation:
To get the unit cost, we'll divide each price by the weight
The first box has a unit cost of (4.69)/450 = 0.010422 approximately which rounds to 0.01; so this unit cost is approximately $0.01 per gram or 1 cent per gram.
For the second box, its unit cost is (6.49)/600 = 0.0108167 approximately. When we round to the nearest cent, we get the same unit cost as before. Without rounding, we see that the first box has a slightly lower unit cost. Therefore box 1 is the better buy.
