20/9 4/3 7/9 4/9 1/4 a.1/6 b.1/9 c.5/36 d.1/144
问题描述：
20/9 4/3 7/9 4/9 1/4 a.1/6 b.1/9 c.5/36 d.1/144
答
20/9 4/3 7/9 4/9 1/4用前一项除以后一项,所得的结果分别为：20/9 * 3/4 = 10/64/3 * 9/7 = 12/77/9 * 9/4 = 14/84/9 * 4/1 = 16/91/4 * = 18/10?= 5/36 所以答案为 C