A housewife didn't know how to estimate the cost of living, so she asked her husband about it。 Her husband said, "It's very simple. Take our income and add 30 per cent." 有个家庭主妇不知道怎样估算他们的生活费用，就去问她的丈夫。 她的丈夫说：“很简单。就是把我们的收入另外加30%”