I’m a new member of this forum and I’m very interested in learning more about the DMRS of different expressions. I have some questions about the phrase “a decade and a half” and its syntactic variations that I hope someone can help me with.
Consider the following DMRS as the preferred semantic interpretation of the phrase
“A decade and a half”, abbreviated as D1.
Problem 1: Replace “a decade” with “one decade” and try pluralize “decade”
1a: One decade and a half does not produce D1
1b: One decades and a half produces D1 but pluralizing decade could be unwanted (?)
Problem 2: Replace “decade” with “apple”
2a: “An apple and a half” does not produce D1
I wonder what’s the difference between an apple and a decade. 
2b: One apples and a half surprisingly produces D1
Problem 3: Replace “decade” with other words
Case 3a: A time and a half produces D1
Case 3b: A space and a half produces D1
Case 3c: A bottle and a half does not produce D1
Problem 4: Why “a quarter” does not produce the predicate fraction(1/4)? (and behave like “a half”)
Thank you!