Swifty Company uses a periodic inventory system. Details for the inventory account for the month of January, 2020 are as follows:

	Units	Per unit price	Total
Balance, 1/1/20	230	$6.00	$1380
Purchase, 1/15/20	170	5.30	901
Purchase, 1/28/20	170	5.30	901

An end of the month (1/31/20) inventory showed that 250 units were on hand. How many units did the company sell during January, 2020?

340

80

250

320