What will come in place of the question mark (?) in the following series?
120, 108, 97, 87, 78, ?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 70
The series falls by uneven steps, so look at the difference between each pair of terms. The drops become one smaller each time:
\(120-108=12\)
\(108-97=11\)
\(97-87=10\)
\(87-78=9\)
The next drop is 8, so the missing term is \(78-8=70\).