Grade 9 Computer Science — Lists and their positions

1.A list can hold a single value and still be a list. What does this program print?

only = [17]
print(len(only) + only[0])

2.Put these lines in order of the value each one gives, smallest first.

items = [40, 10, 30, 20]

• items[3]
• items[0]
• items[1]
• items[2]

3.Two values are read out of this list and added together. What does it print?

nums = [5, 12, 7, 3]
print(nums[1] + nums[3])

4.How many values does the list in this program hold?

counts = [5, 2, 9, 4, 7, 1]
print(len(counts))

5.A list called xs holds 8 values. Which one of these reads the last of them?

• a) xs[len(xs)]
• b) xs[7]
• c) xs[9]
• d) xs[8]

6.This program reads the very first value out of a list. What does it print?

marks = [6, 1, 8, 3]
print(marks[0])

7.A value is copied from one position into another before anything is printed. What does this program print?

row = [1, 2, 3, 4]
row[0] = row[3]
print(row[0] + row[3])

8.The list is the same for all of these. Match each line to the number it prints.

values = [7, 4, 9, 2, 8, 3]