Mathematical philosophy of how much food a person will eat in his life after 60 years.
Five people in my family eat a bag of 50 kilograms of rice a month, so five people eat 12 bags of rice a year * * 12 * 50 = 600 kilograms, so five people eat 600 * 60 = 36,000 kilograms of rice in 60 years, so people will eat: 36,000/5 = 60 years later.