8 9/20 * 2/13 = 169/20 * 2/13 = 13/10 * 1/1 = 13/10 = 1 3/10 = 1,3
5 1/3 * 3/8 = 16/3 * 3/8 = 16/8 = 2
10 1/2 * 2/7 = 21/2 * 2/7 = 21/7 = 3
5/6 * 1 6/5 = 5/6 * 11/5 = 11/6 = 1 5/6
3 1/9 * 3/8 = 28/9 * 3/8 = 7/3 * 1/2 = 7/6
9 1/7 * 3/4 = 64/7 * 3/4 = 16/7 * 3/1 =48/7 = 6 6/7
10 1/5 * 10/17 = 51/5 * 10/17 = 3/1 * 2/1 = 6
3/11 * 5 1/2 = 3/11 * 11/2 = 3/2 = 1 1/2 = 1,5