Question:
Find the missing number in the series: 2, 6, 12, 20, 30, 42, ?
श्रृंखला में लुप्त संख्या: 2, 6, 12, 20, 30, 42, ?
Options:
- a) 56
- b) 58
- c) 60
- d) 64
- a) 56
- b) 58
- c) 60
- d) 64
correct answer : a)
Explanation:
n(n+1): 1×2=2, 2×3=6, 3×4=12, 4×5=20, 5×6=30, 6×7=42, 7×8=56.
n(n+1): 7×8=56।