What number would complete the pattern 14 5 18 24 15 28 34

Sequence:                                      14    5    18    24    15    28    34
difference between each number:    -9   13    6      -9     13     6

The difference between each number goes -9 then 13 then 6 so the next number in the sequence would have difference of -9. Therefore the next number in the sequence would be 25. 

9/12 is the answer because 3/4 times 3 each is 9/12