Find the missing number in the following series.
2, 6, 12, 20, 30, ?, 56
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 42
Each term is the product of two consecutive numbers:
\(1\times2=2\), \(2\times3=6\), \(3\times4=12\)
\(4\times5=20\), \(5\times6=30\)
\(6\times7=42\)
Check: \(7\times8=56\), the last term
So the missing number is 42. (The differences 4, 6, 8, 10, 12, 14 give the same answer.)