Which is the (n)th term of the sequence (7,11,19,35,67,\ldots)?

Correct answer: \(2^{n+1}+3\)

The consecutive differences are \(4,8,16,32\), and each difference doubles. Substituting \(n=1,2,3\) in \(2^{n+1}+3\) gives \(7,11,19\), so it matches the sequence. Although \(2^n+5\) gives the first term, it gives \(9\) when \(n=2\), so it is incorrect. Exam tip: for an exponential sequence, first inspect the pattern of consecutive differences.