Final answer:
The next number in the set is 36. The pattern in the set is to subtract a decreasing number from each previous number. Therefore, to find the next number, we subtract 1 from 25.
Step-by-step explanation:
The next number in the set is 36.
To find the pattern in the set, we can subtract each number from the previous one. From 39 to 34, we subtract 5. From 34 to 30, we subtract 4. From 30 to 27, we subtract 3. From 27 to 25, we subtract 2.
Therefore, to find the next number, we subtract 1 from 25, resulting in 24. However, since the given options do not include 24, we can conclude that the next number is 36.