Angela : 12 miles per hr .... 5280 ft = 1 mile...so 12 miles = (12 * 5280) = 63360 ft 60 seconds per minute....60 minutes per hr.....(60 x 60) = 3600 seconds 63360 / 3600 = 17.6 ft per second
so Ben's rate (15 ft per second) < Angela's rate (12 miles per hr)