[填空题]Think twice next time someone asks you for "five minutes of your time" —it could cost you more than you think. A British professor has (47) a mathematical formula to help people find out (48) how much an hour of their time is worth. Professor Ian Walker of Warwick University (49) the value of time after research showed that over 80 percent of (50) would buy more time if they could afford it. "Traditionally, salaries have (51) an indication of how we are valued at work," Walker, an (52) professor, said in a statement. "However, by looking at salaries against taxation, the cost of living and (53) variations, we can see how much an hour of our time is worth whether at work or home." The formula could help in making (54) , such as whether to cook a meal or to get a takeaway, or whether to take (55) transport or a taxi. Visitors to www. Barclaycard. co. uk/timeismoney can find out the value of