At the grocery store, one brand of ice cream costs $4.50 for 48 ounces. The same brand costs $7 for 128 ounces or $3 for 64 ounces. Which size has the lower unit price?

Answer 1

To find the unit price, we divide the cost by the number of ounces.

For the size costing $4.50 for 48 ounces, the unit price is $4.50/48 = $<<4.50/48=0.094>>0.094 per ounce.

For the size costing $7 for 128 ounces, the unit price is $7/128 = $<<7/128=0.055>>0.055 per ounce.

For the size costing $3 for 64 ounces, the unit price is $3/64 = $<<3/64=0.047>>0.047 per ounce.

Therefore, the size with the lower unit price is the one that costs $3 for 64 ounces. Answer: \boxed{64}.