5. When we use the divide-and-conquer view on the mergesort and the quicksort, for which one, the divide step is more expensive (in the sense of computing time) than the combine step? (a) mergesort (b) quicksort 6. Given an array with 5 elements, is it true that one can always use 3 comparisons to determine an element that is among the top two? (a) yes (b) no 7. Given an ordered array with n elements, which of the following expressions gives the worst-case efficiency for the binary search? (a) log2n (b) log2n (c) log2(n+1) (d) log2(n+1) 8. Given an array with n elements, we want to find the second largest element in this array. In order to find the second largest element, do we have to find the largest element first? (a) yes (b) no