1. 6:(3/5)=6/0,6=10.
2. 1¹/₆*6/7=(7/6)*(6/7)=1.
3. 10-1=9.
4. 4¹/₅*10/11=(21/5)*10/11=42/11.
5. (42/11)+5²/₁₁=(42/11)+(57/11)=99/11=9.
6. 9/9=1.
7. 3/20+1/2-1/15=(3*3+1*30-1*4)/60=(9+30-4)/60=35/60=7/12.
8. (7/12)*(12/49)=1/7.
9. 1/5+1/7=(5+7)/35=12/35.
10. (1/7):(12/35)=1*35/(7*12)=5/12.
11. 1-(5/12)=7/12.
12. (7/12)*2¹/₃=(7/12):(7/3)=3/12=1/4.
13. 3¹/₄-1/4=3.