Which number will replace the question mark (?) in the following series?
37, 48, 65, 80, 101, 120, ?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 145
The terms lie close to the squares 36, 49, 64, 81, 100, 121. Each term is one more and one less than a square, alternately:
\(6^2+1=37\), \(7^2-1=48\)
\(8^2+1=65\), \(9^2-1=80\)
\(10^2+1=101\), \(11^2-1=120\)
The 7th term is \(12^2+1=144+1=145\)
So the missing number is 145.