7 1/7*3 1/2=50/7·7/2=50/2=25

10 1/22*1 1/3=221/22·4/3=221·4/22·3=221·2/11·3=442/33=13 13/33

1 7/10*3 1/3=17/10·10/3=17·10/10·3=17/3=5 2/3

8 2/3*1 2/13= 26/3·15/13=26·15/3·13=2·5/1=10