Final answer:
To determine the cash flow from operating activities for Armstrong Company, use the indirect method. Start with net income and adjust for non-cash expenses and changes in working capital.
Step-by-step explanation:
To determine the cash flow from operating activities for Armstrong Company using the indirect method, we start with the net income and adjust for non-cash expenses and changes in working capital.
Net income: $450
Add back depreciation expense: $80
Decrease in accounts receivable: $20
Decrease in accounts payable: $30
Cash flow from operating activities: $450 + $80 + $20 - $30 = $520
Therefore, the correct answer is a. $520.