Question

Assume that play_list refers to a non-empty list, and that all its elements are integers. Write a statement that associates a new value with the first element of the list. The new value should be equal to twice the value of the last element of the list.

Answer 1

To set the first element of a list to twice the value of the last element, use the statement play_list[0] = play_list[-1] * 2 in Python. This utilizes negative indexing to access the last item of the list.

Step-by-step explanation:

To associate a new value with the first element of a non-empty list of integers in Python, where the new value is twice the value of the last element of the list, you can use the following Python statement:

play_list[0] = play_list[-1] * 2

This line will access the first element of the play_list using play_list[0] and assign it a new value which is twice the last element's value, accessed via play_list[-1]. The index -1 is used in Python to refer to the last element in a list.

Answer 2

The solution code is written in Python.

1. play_list = [2, 4, 6, 8, 10]
2. play_list[0] = 2 * play_list[len(play_list) - 1]
4. print(play_list)

Step-by-step explanation:

Firstly, we create a non-empty list, play_list, and fill it up with five random integers (Line 1).

To associate the new value with the first element of the list, we use expression play_list[0]. The index 0 address to the first element of the list.

Next, we use expression, len(play_list) - 1 to get the last index of the list and use that calculated last index to take out the last element and multiply it with 2. The result of multiplication is assigned to the first element, play_list[0] (Line 2).

When we print the list, we shall get

[20, 4, 6, 8, 10]