Answer: There were 40 euros in the drawer at the beginning.
Explanation:
When we subtract 6 from 16, we get 10 more ice-creams were sold.
Similarly, we subtract 70 from 120, we get 50 euros was the total selling price of 10 ice-creams.
i.e. Selling price of 1 ice-cream = (50)÷10 =5 euros
Selling price of 6 ice-creams = 6 x 5 = 30 euros
Money in the drawer at the beginning = 70-30 = 40 euros
Hence, there were 40 euros in the drawer at the beginning.