As an example, mergesort and quicksort each partition their input into two subarrays ("divide"), which are then sorted recursively and put together ("conquer"). In the case of mergesort, divide is trivial and conquer requires work. The opposite is true for quicksort. The running times of both algorithms satisfies the recurrence $$T(n) = 2T(n/2) + \Theta(n)$$, whose solution is $$\Theta(n\log n)$$.