Mrs. cain is researching what it would cost to order flower arrangements for a fancy party. she wants one large centerpiece for the head table, and smaller arrangements for the smaller tables. newport florist charges $10 for each smaller arrangement, plus $40 for the large centerpiece. samuel's flowers, in contrast, charges $30 for the large centerpiece and $12 per arrangement for the rest. if mrs. cain orders a certain number of small arrangements, the cost will be the same at either flower shop.
How many small arrangements would that be?