please solve these questions and could you write the number of answer in each question:

Complete the practice exercises (from page 687 of Big Java: Late Objects):

1.Modify the selection sort algorithm to sort an array of integers in descending order.

2.Modify the selection sort algorithm to sort an array of coins by their value.

3.Modify the insertion sort algorithm to sort an array of integers in descending order.

4.Modify the merge sort algorithm to sort an array of strings in lexicographic order.