justify the statement that "Grouping the objects helps the shopkeeper".

Yes ,grouping objects is helpful for shopkeeper as well as for us because if we want to buy ketchup we would go to the food section of the shop to take it. So it helps to buy things.

For shopkeepers, if someone asks him to get a particular thing for him/her. So he would go to the particular section of the shop to bring it. So it helps the shopkeeper also.