Clarifying question:

1. Type of the grocery store: large super market, or specialized grocery store?

2. Type of food sold in the store

3. Does the count include the items on the shelf? or in the storage as well?

4. Does it include refridgrated items? or not?

This question has a lot of categories to break into, and listing a few as examples:

Let’s assume only calculating the items in the store (not in the storage), and it’s a small store (like 7-11)

1. Snacks (bars, small bags of chips, cookies, candies etc) => about 200 calories per item, about 400

2. Bread and packaged foods => 2500 cal per item, about 400

3. Drinks (small) => 200 cal per item, 200

4. Drink (large) => 1500 cal per item, 100

8. Cakes/pies => 3000 cal per item, 40

Now, estimate the number of items in each category, and cross check with total weight

That gives 2740kcal.

Cross check: protein 4 cal per gram, carbs 4 cal per gram, and fat 9 cal per gram

A classic estimation question for PM candidates.

I am assuming its a small grocery store like 7/11. Now breaking down the problem.

Total calorie = Volume of food in grocery store * Calorie per unit volume

Volume of food in grocery store = # of rows of food * # food volume per row

Assuming 10 racks, 2 faces per rack, 3 rows on each face of the rack

# of rows = 60

Assuming row dimension. = 40ft(long) * 2 ft (high) * 2 ft (deep), 80 % food occupancy

# food volume per row = 128 cu. ft.

So volume of food in grocery store = 60 * 128 = 7680cu.ft.

To find calorie per unit volume, lets divide the items in the grocery store with the calorie density as

We will find the calorie per unit volume of dairy products(high density) and derive the Medium and low relative to it.

1 litre milk = 100 cal

1 cu. ft = 30 l = 3000 cal

1 cu. ft (high density) = 3000 cal

1 cu. ft (medium density) = 1500 cal

1 cu. ft (low density) = 750 cal