Complete the series: 12, 20, 30, 42, 56, ?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 72
Each term is the product of two consecutive numbers, starting with 3 and 4:
\(12=3\times4\), \(20=4\times5\), \(30=5\times6\)
\(42=6\times7\), \(56=7\times8\)
Next: \(8\times9=72\)