B. 285/302. This is the correct answer because it is the only choice which is roughly the same ratio as 47.5/50.5 which is the ratio needed to determine how long it would take to go 47 1/2 miles in a car that averages 50 1/2 miles per hour. The mathematical equation which represents the problem is: 50.5/1 = 47.5/A (A = hours) which is the same as 50.5 A = 47.5 which means A = 47.5/50.5 which means A = .94 hours. 285/302 also equals .94.