| 100% | PASSFAIL | 8 | Grading system with only two options: Hyph. |
| 55% | EITHEROR | 8 | Situation with only two options |
| 54% | BINARY | 6 | Number system with only two symbols |
| 50% | YESNO | 5 | Like questions with only two possible answers: Hyph. |
| 49% | YESNO | 5 | Type of question with only two possible answers: Hyph. |
| 45% | YESNO | 5 | Question type with only two answers (Hyph.) |
| 44% | YESNO | 5 | Like questions with only two possible answers (hyph.) |
| 42% | YESNO | 5 | Type of question with only two answers (Hyph.) |
| 42% | PASSFAIL | 8 | Two-option grading system |
| 40% | NEPAL | 5 | Landlocked land with only two neighbors |
| 39% | YESNO | 5 | Kind of question with only two answers |
| 39% | RONDEL | 6 | 14-line poem with only two rhymes |
| 39% | NMI | 3 | Abbr. for someone with only two names |
| 39% | RONDEL | 6 | 14-line verse with only two rhyme sounds |
| 38% | BASETWO | 7 | Number system with only 0's and 1's |
| 38% | STEREOSET | 9 | Sound system with two speakers |
| 37% | RONDEL | 6 | 14-line poem with only two rhymes across three stanzas |
| 36% | STEREOS | 7 | Sound system with two or more speakers |
| 36% | STEREO | 6 | Sound system with two or more speakers |
| 36% | BINARY | 6 | Star system with two stars orbiting each other |
| 35% | IOWA | 4 | Only state name beginning with two vowels |
| 35% | LAHR | 4 | Only ''Oz'' actor with two solo songs |
| 35% | SWIRL | 5 | Froyo option with two flavors |
| 34% | OBAMA | 5 | One of only two presidents with two Ivy League degrees |
| 34% | IOWA | 4 | Only state whose name starts with two vowels |
| 34% | ELAL | 4 | Only commercial airline with onboard missile defense systems |
| 34% | MOZAMBIQUE | 10 | Only nation spelled with two 10-point Scrabble letters |
| 33% | PRANCER | 7 | Santa's only reindeer with two Rs |
| 33% | BINARYCODE | 10 | *System with only ones and zeros |
| 33% | NOV | 3 | Besides Jan., only month with two federal holidays |