Look at the series 15, 30, 23, 46, 39, 78, ___
2023
Look at the series 15, 30, 23, 46, 39, 78, ___
- A.
76
- B.
71
- C.
72
- D.
69
Attempted by 28 students.
Show answer & explanation
Correct answer: B
Solution: The sequence alternates between multiplying by 2 and subtracting 7.
15 × 2 = 30
30 − 7 = 23
23 × 2 = 46
46 − 7 = 39
39 × 2 = 78
Next: 78 − 7 = 71, so the missing term is 71.