What fraction of the US states' names include only one word?

Answer 1

40 of the 50 states have one-word names. The ones that have two words are : New Hampshire, New Jersey, New Mexico, New York, North and South Carolina, North and South Dakota, West Virginia, and Rhode Island.

Answer 2

US 50 States' names are, in alphabetical Order

1. Alabama
2. Alaska
3. Arizona
4. Arkansas
5. California
6. Colorado
7. Connecticut
8. Delaware
9. Florida
10. Georgia
11. Hawaii
12. Idaho
13. Illinois
14. Indiana
15. Iowa
16. Kansas
17. Kentucky
18. Louisiana
19. Maine
20. Maryland
21. Massachusetts
22. Michigan
23. Minnesota
24. Mississippi
25. Missouri
26. Montana
27. Nebraska
28. Nevada
29. New Hampshire **
30. New Jersey **
31. New Mexico **
32. New York **
33. North Carolina **
34. North Dakota **
35. Ohio
    
36. Oklahoma
37. Oregon
38. Pennsylvania
39. Rhode Island **
40. South Carolina **
41. South Dakota **
42. Tennessee
43. Texas
44. Utah
45. Vermont
46. Virginia
47. Washington
48. West Virginia
49. Wisconsin
50. Wyoming

Two word State names only:

1. New Hampshire **
2. New Jersey **
3. New Mexico **
4. New York **
5. North Carolina **
6. North Dakota **
7. Rhode Island **
8. South Carolina **
9. South Dakota **

9/50 US States have 2 names. 41/50 US States have one name

Answer 3

I assume you're asking about their common names. 41/50 of the states have one-word common names. Officially, many one-word states have longer names, like the Commonwealth of Pennsylvania or the State of Rhode Island and Providence Plantations.