What is the missing term ?3, 8, 15, 24, ?, 48.

The correct answer is Option (3) → 35

Each term is one less than a perfect square, the squares running 4, 9, 16, 25, ... (the squares of 2, 3, 4, 5, ...).

• \(3=2^2-1,\ 8=3^2-1,\ 15=4^2-1,\ 24=5^2-1\)

• Missing term: \(6^2-1=35\)

• The last term fits the rule: \(7^2-1=48\)

The same series can be read through its differences, 5, 7, 9, 11, 13, which grow by 2: \(24+11=35\) and \(35+13=48\).