13. 2 is the relation of what units?
14. 3 is the relation of what units?
15. 1⁄2 is the relation of what units?
16. 2⁄3 is the relation of what units?
17. Which units have the relation 3⁄2?
18. Which unit is 3 times as large as 1⁄2 of b?
19. c equals 6 times 1⁄3 of what unit?
20. 1⁄3 of what unit equals 1⁄6 of c?
21. What equals 1⁄2 of c? d equals how many sixths of c?
22. o equals 5 times 1⁄3 of what unit?