22 and 1 / 20 * 1 / 21 22 20/1*21/1

22 and 1 / 20 * 1 / 21 22 20/1*21/1

(22 1 / 20) × (1 / 21) = (441 / 20) × (1 / 21) = 21 / 20 = 1 / 20