Answer:
23
46
99
1/3
1/2
7/8
Explanation:
Let's find out by writing out each of the numbers.
17 = Seventeen (Seventeen stands alone)
20 = Twenty (Twenty stands alone)
23 = Twenty-three will be hyphenated
46 = Forty-six will be hyphenated
99 = Ninety-nine will be hyphenated
1/3 = one-third will be hyphenated
1/2 = one-half will be hyphenated
7/8 = seven-eights will be hyphenated
Now we ask ourselves why are they hyphenated?
We hyphenate because we need the two words to be glued together to show readers that the two or more elements of a sentence are link to each other.