Answer 1

To get last value in the list, one need to index from the back using negative value

Example:

nums = [2, 4, 6, 8, 10]

nums[-1] = 10 The last value
nums[:-1] = 2, 4, 6, 8 subtracts the last value
nums[::-1] = 10, 8, 6, 4, 2 reverse the list from the last value