Answer:
Yes he was correct in returning the 100
Explanation:
Pen 68.75
Pencil 73.50
Paint box 112.35
Add all together, you get 254.60
If he paid 500 to the shopkeeper, he will collect (500.00-254.60) =245.40
If the shopkeeper gave him 345.40, then he had an excess and should give back the 100