Give an answer to those two questions.

Consider the recursive version of Mergesort with no modifications. Which of the following pairs are correct statements for the best case and the worst-case running time of Mergesort on an array of size n ? a) O(n),(nlogn) b) (n2),O(nlogn) c) (nlogn),(n1.5) d) (nlogn),O(nlogn) e) (n),O(n2) Question 4 Let 5 be an empty stack. Consider a sequence of intermixed push and pop calls on 5 . The arguments for the push calls are the letter: A, B, C, D, E, F and G (one at a time in that order). The pop calls happen at arbitrary time (when 5 is not empty) and each pop prints out the returned value. Check all printed sequences that are possible. a) BDACEFG b) GFEDCBA c) ABDCEFG d) CBGFEAD