Sandra has a bright idea: When the length of a sublist in quicksort is less than a certain number—say, 30 elements—run an insertion sort to process that sublist. Explain why this is a bright idea. Why...

Sandra has a bright idea: When the length of a sublist in quicksort is less than a certain number—say, 30 elements—run an insertion sort to process that sublist. Explain why this is a bright idea. Why is merge sort an O(n log n) algorithm in the worst case?