| Question | Select the set in which the numbers are related in the same way as are the numbers of the following set (7, 13, 21) | |
| Type | multiple_choice | |
| Option | (12, 18, 25) | incorrect |
| Option | (17, 22, 30) | incorrect |
| Option | (9, 16, 25) | incorrect |
| Option | (2, 8, 16) | correct |
| Solution | Difference of 6 and 8 | |
