..................=1 247/2600
1) 1 17/18 * 1 13/14=35/18 * 27/14=15/4=3 3/4
2) 2 5/8 : 1 19/20=21/8 * 20/39=35/26=1 9/26
3) 3 3/4 - 1 9/26=3 39/52 - 2 18/52=1 21/52
4) 2 25/78 - 1 1/26=2 25/78 - 1 3/78=1 22/78=1 11/39
5) 1 21/52 : 1 11/39=73/52 * 39/50=2847/2600=1 247/2600