Radius of a wheel = 13 inch = 1.08333 ft circumference of a wheel = 2×pi×r^2 = 2 × (22/7) × 1.08333^2 ft = 2 × (22/7) × 1.1736 ft = (44/7)×1.1736 ft = 51.6384/7 ft = 7.3769142857 ft distance covered in one minute = 37 × 60 ft/min = 2220 ft/min now, revolution per minute = 2220 / 7.3769142857 = 300.93884 therefore her wheels are making 300.93884 revolutions per minute