There are two individuals in an economy, Joe and Mary. Each of them is currently consuming positive amounts of two goods, food and clothing. Their preferences are characterized by diminishing marginal rate of substitution of food for clothing. At the current consumption baskets, Joe's marginal rate of substitution of food for clothing is 2, while Mary's marginal rate of substitution of food for clothing is 0.5. Do the currently consumed baskets satisfy the condition of exchange efficiency? If not, describe an exchange that would make both of them better off.