2/5 : 1 3/5=2/5 : 8/5=2/5 * 5/8=2/8=1/4 1/4: 1 3/8=1/4: 11/8=1/4* 8/11=2/11 2/11: 1 3/11= 2/11: 14/11=2/11* 11/14=2/14=1/7 Ответ:1/7