First calculate the circumference. Usually this is the diameter times pi, but since we are told to estimate pi, the circumference equals 56 * 22/7 or 176 feet.
In 4 minutes, 4 * 60 = 240 seconds pass. In this time, a 20 second period will occur 240/20 = 12 times.
So we know that the rider rotates 12 times and each rotation takes them 176 feet, meaning that they will travel 12 * 176 = 2112 feet