| Question | Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number- pair that is different. | |
| Type | multiple_choice | |
| Option | 61 | incorrect |
| Option | 109 | incorrect |
| Option | 73 | incorrect |
| Option | 91 | correct |
| Solution | Except (d) all other are prime numbers | |
