Final answer:
The average cost of one handbag in that month was $220.
Step-by-step explanation:
To find the average cost of one handbag, we can use the average cost function C(x) = (20x + 150000) / x, where x is the number of handbags manufactured. For this problem, x = 3500. Plugging in x = 3500 into the function, we get C(3500) = (20 * 3500 + 150000) / 3500 = 220. Therefore, the average cost of one handbag in that month was $220.