Answer:
10 cartons
Explanation:
Shopping trip = $2
Holding cost per carton per month = $0.2
Demand (monthly) = 5 cortons per month
When family buy 10 cartons /month
Total cost = $2 (trip cost) + $0.2x10 (1st month inventory holding cost) +0.2x5 (2nd month inventory holding cost) = $5
When family buy 5 cartons/month
Total cost for 2 months = $2 + $0.2 x 5 + $2 + $0.2 x 5 = $6
Buying 10 cartons is $1 cheaper than buying 5 cartons for 2 months