Answer: Your question is missing information but this is what you do to answer your question step by step
B = Cost of 8 pack / 8 bottles = $ Cost of 8 pack/ 8 =$ ____ per bottle
A = Cost of 6 pack/ 6 bottles = $ Cost of 6 pack/ 6= $ ____ per bottle
then do a simple subtraction A -B = savings
Step-by-step explanation: Information is incomplete
if an 8 pack cost $16
If the 6 pack cost $15
All you do is a simple subtraction after calculations
Cost of 8 pack / 8 bottles = $16/8 =$2 per bottle
Cost of 6 pack/ 6 bottles = $15/ 6= $2.50 per bottle
in my example
You would save $ 0.50 per bottle by purchasing the 8 pack