Amarketing firm determined that, of 200 households surveyed, 80 used neither brand a nor brand b soap, 60 used only brand a soap, and for every household that used both brands of soap, 3 used only brand b soap. how many of the 200 households surveyed used both brands of soap?

Ivan, a russian fishermen, needs a permit so that he can commercially participate in ice fishing for yellow perch and then the consequent sales. garet is an undergraduate student who has to work at mcdonald\'s part time to pay his tuition loans. always looking on the bright side of things, he is that he can\'t make less than what he is earning, $7.25 an hour. d\'artagnan, a poor french noblemen, discovers a large cache of truffles in his backyard. however, the government caps the sale of truffles at $100 a pound, which frustrates d\'artagnan as he knows they are worth more than that. athos is an avid collector of swords, but as they are illegal to purchase, he goes by illicit means to obtain them. to out irish farmers, the government sets the minimum price of potatoes at $26 a bushel. in order to support domestic sales of textiles, the country of germany puts a cap on the amount of foreign textiles it imports.