Choose the number that will come next in the following series.
5, 12, 8, 15, 11, 18, ?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 14
The series goes up and down in turn, so look at the steps: they are +7 and −4 alternately.
\(5+7=12\), \(12-4=8\)
\(8+7=15\), \(15-4=11\)
\(11+7=18\)
The next step is −4: \(18-4=14\)
So the next number is 14.