The amount of fuel he uses follows a normal distribution for each part of his commute, but the amount of fuel he uses on the way home varies more. The amounts of fuel he uses for each part of the commute are also independent of each other. Here are summary statistics for the amount of fuel Shinji uses for each part of his commute. So when he goes to work, he uses a mean of 10 liters of fuel with a standard deviation of 1.5 liters. And on the way home, he also has a mean of 10 liters, but there is more variation, there is more spread. He has a standard deviation of two liters. Suppose that Shinji has 25 liters of fuel in his tank and he intends to drive to work and back home.