we are given two cases
ABC Electronics:
total number of AA pack of batteries = 8
total cost price =$4.80
cost per battery = (total cost price)/(total number of AA pack of batteries)
cost per battery =

Better Batteries:
total number of AA pack of batteries = 15
total cost price =$10.20
cost per battery = (total cost price)/(total number of AA pack of batteries)
cost per battery =

We always look for lesser cost
so, ABC Electronics deal is better
Difference in cost per battery =0.68-0.60
Difference in cost per battery =$0.08..........Answer