350 x 30% = 105 (Adam manages 30% of total stocks)
350 – 100 – 105 = 145
145/500 = 29%
This is where we stop. No need to calculate further.
What’s good about this solving method is that it shows you EXACTLY the data you need to find, as well as how simple it is to calculate with the horizontal-and-vertical structure of the table.