Which term of the arithmetic progression $5, 9, 13, 17, \ldots$ is equal to 101?

The $n$th term is $5 + 4(n - 1)$. Setting this equal to 101: $4(n - 1) = 96$, so $n - 1 = 24$ and $n = 25$. Forgetting to add 1 after dividing gives the 24th term, which is actually 97.