Choose the number that will replace the question mark (?) in the following series.
3, 40, 6, 35, 12, 30, 24, ?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 25
The terms jump up and down, so read the terms in odd places and in even places as two separate series:
Odd places: 3, 6, 12, 24, each twice the one before
Even places: 40, 35, 30, ?, each 5 less than the one before
The question mark is in the 8th place, an even place, so it is \(30-5=25\).