Tables, rows, and columns concept in Intro to Computing - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a table with 3 columns.

Intro to Computing

table = [['Name', 'Age', [1]], ['Alice', 30, 'Engineer'], ['Bob', 25, 'Designer']]

Drag options to blanks, or click blank then click option'

AOccupation

BSalary

CCountry

DCity

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a column name that doesn't match the data in the rows.

Using a column name unrelated to the example data.

The third column header should be 'Occupation' to match the data in the rows.

2fill in blank

medium

Complete the code to access the age of the second person in the table.

Intro to Computing

age = table[[1]][1]

Drag options to blanks, or click blank then click option'

A0

B1

C2

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 which accesses the header row instead of data.

Using 2 which accesses the third person who does not exist.

table[1] accesses the second row (first row is headers), and [1] accesses the 'Age' column.

3fill in blank

hard

Fix the error in the code to print the job of the first person.

Intro to Computing

print(table[1][[1]])

Drag options to blanks, or click blank then click option'

A2

B1

C0

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using index 3 which is out of range.

Using index 1 which is the age, not the job.

The job is in the third column, which is index 2 (0-based indexing).

4fill in blank

hard

Fill both blanks to create a new row and add it to the table.

Intro to Computing

new_row = ['Charlie', [1], [2]]
table.append(new_row)

Drag options to blanks, or click blank then click option'

A28

B'Teacher'

C'Doctor'

D35

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the order of age and occupation.

Using a string for age or a number for occupation.

The new row needs an age (28) and an occupation ('Teacher') to match the table structure.

5fill in blank

hard

Fill all three blanks to create a dictionary from the table row with keys as columns.

Intro to Computing

row_dict = {table[0][[1]]: table[1][[2]], table[0][[3]]: table[1][2]}

Drag options to blanks, or click blank then click option'

A0

B1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing row and column indexes.

Using the same index for both keys and values incorrectly.

The dictionary keys come from the header row (index 0), and values from the first data row (index 1). The first key-value pair uses column 0 and 1, the second uses column 2 and 2.

Practice

1. What does a row in a table represent?

easy

A. A vertical set of data values under a category

B. A single record or entry containing data across columns

C. The title or heading of the table

D. A summary of all data in the table

Solution

1. Step 1: Understand the structure of a table

   A table is made of rows and columns where rows run horizontally and columns run vertically.

2. Step 2: Identify what a row holds

   A row holds one complete record or entry, with data spread across the columns.

3. Final Answer:

   A single record or entry containing data across columns -> Option B

4. Quick Check:

   Row = record [OK]

Hint: Rows are horizontal records; think of a single spreadsheet line [OK]

Common Mistakes:

• Confusing rows with columns
• Thinking rows are vertical
• Assuming rows are headings

2. Which of the following correctly describes a column in a table?

easy

A. A horizontal set of data values representing a record

B. The total number of rows in the table

C. A vertical set of data values under a specific category

D. The space between two rows

Solution

1. Step 1: Recall the orientation of columns

   Columns run vertically in a table and group data by category or type.

2. Step 2: Define what a column holds

   A column contains all data values under one category, stacked vertically.

3. Final Answer:

   A vertical set of data values under a specific category -> Option C

4. Quick Check:

   Column = vertical category [OK]

Hint: Columns go up and down; think of spreadsheet headers [OK]

Common Mistakes:

• Mixing columns with rows
• Thinking columns are horizontal
• Confusing columns with spacing

3. Consider this table:

ID	Name	Age
1	Alice	30
2	Bob	25
3	Charlie	35

What is the value in the second row and third column?

medium

A. 25

B. Bob

C. Charlie

D. 30

Solution

1. Step 1: Identify the second row

   The first row after the header is row 1 (Alice), so the second row is Bob's data.

2. Step 2: Locate the third column in that row

   The columns are ID (1), Name (2), Age (3). The third column is Age, so the value is 25.

3. Final Answer:

   25 -> Option A

4. Quick Check:

   Row 2, Column 3 = 25 [OK]

Hint: Count rows after header and columns left to right [OK]

Common Mistakes:

• Counting header as first data row
• Mixing column order
• Choosing name instead of age

4. A table has 5 columns and 4 rows (excluding the header). A user tries to access the value at row 6, column 3. What is the likely issue?

medium

A. The value at row 6, column 3 is empty

B. The column number is out of range; column 3 does not exist

C. The table has no rows or columns

D. The row number is out of range; row 6 does not exist

Solution

1. Step 1: Check the number of rows

   The table has 4 rows of data, so row 6 is beyond the last row.

2. Step 2: Check the column number

   There are 5 columns, so column 3 is valid.

3. Final Answer:

   The row number is out of range; row 6 does not exist -> Option D

4. Quick Check:

   Row 6 > 4 rows [OK]

Hint: Check if row or column number exceeds table size [OK]

Common Mistakes:

• Confusing row and column limits
• Assuming missing rows exist
• Thinking empty means valid

5. You have a table with columns: Product, Price, and Quantity. How would you calculate the total value of all products using rows and columns?

hard

A. Multiply Price and Quantity for each row, then sum all results

B. Sum all values in the Quantity column only

C. Count the number of rows and multiply by Price

D. Add all values in the Price column only

Solution

1. Step 1: Understand the data in each row

   Each row has a product with its Price and Quantity.

2. Step 2: Calculate total value per product

   Multiply Price by Quantity for each row to get that product's total value.

3. Step 3: Sum all product totals

   Add all these per-row totals to get the overall total value.

4. Final Answer:

   Multiply Price and Quantity for each row, then sum all results -> Option A

5. Quick Check:

   Total = Σ (Price x Quantity) [OK]

Hint: Multiply then add per row for total value [OK]

Common Mistakes:

• Adding prices without quantities
• Multiplying total rows by price
• Ignoring quantity in calculation