World's Richest man,Carlos Slim Helú says we should work only 3 times a week

World's Richest man,Carlos Slim Helú, the Mexican telecommunications mogul worth approximately $79.6 billion,is advising people to take more time off in their professional lives and work only three times a week, instead of the standard five... Speaking at a business conference in Paraguay,the 74 year old said....
'People are going to have to work for more years, until they are 70 or 75, and just work three days a week – perhaps 11 hours a day,'With three work days a week, we would have more time to relax; for quality of life. Having four days [off] would be very important to generate new entertainment activities and other ways of being occupied,'
How practicable is this?