A60 ounce glass bottle of juice sells for $4.20 while a 1.5 liter of the same juice sells in a plastic bottle for $3.06. compare the unit prices of the juice for the two containers. (1 liter is approximately 34 ounces)
a. the juice in the glass bottle is 1 cent cheaper per ounce.
b. the juice in the plastic bottle is 1 cent cheaper per ounce.
c. the juice in the glass bottle is 10 cents cheaper per ounce.
d. the juice in the plastic bottle is 10 cents cheaper per ounce.

We first convert 1.5 Liters of bottled juice  to units of ounce so we can compare the two. 

1.5 L plastic bottled juice ( 34 oz / 1 L) = 51 oz of plastic bottled juice

We then divide the prices of each juice to their corresponding volume to get a units of dollars per ounce.

$4.20 / 60 oz of glass bottled juice = 0.07 dollars per ouce of glass bottled juice

$3.06 / 51 oz of plastic bottled juice = 0.06 dollars per ounce of plastic bottled juice

Thus, the answer is b. The plastic bottled juice is cheaper by 1 cent compared to the glass bottled juice. 

The answer to this one is c

They carry out the exchange of gases as we breathe ( oxygen and carbon dioxide).