Removing duplicates in Excel - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the formula to remove duplicates from the range A1:A10.

Excel

=UNIQUE([1])

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

AA10:A20

BB1:B10

CA1:A1

DA1:A10

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single cell instead of a range.

Selecting the wrong column range.

The UNIQUE function removes duplicates from the specified range. Here, we want to remove duplicates from A1 to A10, so the correct range is A1:A10.

2fill in blank

medium

Complete the formula to remove duplicates from the range B2:B20 and sort the results.

Excel

=SORT(UNIQUE([1]))

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

AB2:B20

BA1:A10

CC1:C10

DB1:B10

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong range inside UNIQUE.

Forgetting to wrap UNIQUE inside SORT.

The formula first removes duplicates from B2:B20 using UNIQUE, then sorts the unique values with SORT.

3fill in blank

hard

Fix the error in the formula that tries to remove duplicates from C1:C15 but is missing a function.

Excel

=[1](C1:C15)

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

AREMOVE

BUNIQUE

CFILTER

DSORT

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent function like REMOVE.

Using FILTER which filters by condition but does not remove duplicates.

The UNIQUE function is used to remove duplicates from a range. REMOVE is not a valid Excel function.

4fill in blank

hard

Fill both blanks to create a formula that removes duplicates from D1:D20 and returns only values greater than 10.

Excel

=FILTER(UNIQUE([1]), [2] > 10)

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

AD1:D20

BC1:C20

CUNIQUE(D1:D20)

Attempts:

3 left

💡 Hint

Common Mistakes

Using UNIQUE inside the second blank which expects a range.

Using the wrong range in either blank.

The UNIQUE function removes duplicates from D1:D20. The FILTER function then returns only those unique values greater than 10 by comparing the range D1:D20 to 10.

5fill in blank

hard

Fill all three blanks to create a formula that removes duplicates from E1:E30, sorts them descending, and returns only values less than 50.

Excel

=FILTER(SORT(UNIQUE([1]), , [2]), [3] < 50)

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

AE1:E30

BFALSE

DTRUE

Attempts:

3 left

💡 Hint

Common Mistakes

Using TRUE instead of FALSE for descending sort.

Using the wrong range in the filter condition.

The UNIQUE function removes duplicates from E1:E30. SORT sorts the unique values descending by using FALSE for ascending argument. FILTER returns only values less than 50 from the range E1:E30.

Practice

1. What does the Remove Duplicates feature in Excel do?

easy

A. It deletes repeated entries and keeps only unique values.

B. It sorts the data alphabetically.

C. It highlights duplicate cells without removing them.

D. It copies data to another sheet.

Solution

1. Step 1: Understand the purpose of Remove Duplicates

   This feature is designed to clean data by deleting repeated entries.

2. Step 2: Identify what remains after using Remove Duplicates

   Only unique values remain in the list after duplicates are removed.

3. Final Answer:

   It deletes repeated entries and keeps only unique values. -> Option A

4. Quick Check:

   Remove Duplicates = Keeps unique values [OK]

Hint: Remove Duplicates deletes repeats, leaving unique values only [OK]

Common Mistakes:

• Thinking it only highlights duplicates
• Confusing it with sorting
• Assuming it copies data instead of removing duplicates

2. Which of these is the correct way to start removing duplicates in Excel?

easy

A. Go to the Data tab and click Remove Duplicates.

B. Go to the Home tab and click Sort.

C. Right-click a cell and select Insert Comment.

D. Use the Formulas tab and select Calculate Now.

Solution

1. Step 1: Locate the Remove Duplicates feature

   It is found under the Data tab in Excel's ribbon menu.

2. Step 2: Confirm the correct action to remove duplicates

   Clicking Remove Duplicates under Data tab starts the process.

3. Final Answer:

   Go to the Data tab and click Remove Duplicates. -> Option A

4. Quick Check:

   Remove Duplicates is under Data tab [OK]

Hint: Find Remove Duplicates under Data tab, not Home or Formulas [OK]

Common Mistakes:

• Looking under Home tab instead of Data
• Confusing Remove Duplicates with Sort
• Trying to remove duplicates via formulas tab

3. You have this list in column A:
Apple
Banana
Apple
Orange
Banana
After using Remove Duplicates on column A, what will the list look like?

medium

A. Apple, Banana, Apple, Orange, Banana

B. Apple, Banana, Orange

C. Orange, Banana, Apple

D. Apple, Orange

Solution

1. Step 1: Identify duplicates in the list

   The list has Apple twice and Banana twice.

2. Step 2: Remove repeated entries keeping only unique values

   After removal, only one Apple, one Banana, and one Orange remain.

3. Final Answer:

   Apple, Banana, Orange -> Option B

4. Quick Check:

   Duplicates removed = Apple, Banana, Orange [OK]

Hint: Remove duplicates keeps one of each unique item [OK]

Common Mistakes:

• Expecting duplicates to remain
• Thinking order changes randomly
• Removing unique items by mistake

4. You tried to remove duplicates from a table with columns Name and Email, but duplicates still appear. What is the likely mistake?

medium

A. You sorted the table instead of removing duplicates.

B. You used the Undo button after removing duplicates.

C. You only selected one column instead of both before removing duplicates.

D. You applied Remove Duplicates on a blank sheet.

Solution

1. Step 1: Understand how Remove Duplicates works with multiple columns

   It checks duplicates based on selected columns only.

2. Step 2: Identify the mistake of selecting only one column

   If only one column is selected, duplicates in other columns remain.

3. Final Answer:

   You only selected one column instead of both before removing duplicates. -> Option C

4. Quick Check:

   Select all relevant columns to remove duplicates correctly [OK]

Hint: Select all columns to check before removing duplicates [OK]

Common Mistakes:

• Selecting only one column in multi-column data
• Confusing sorting with removing duplicates
• Trying to remove duplicates on empty data

5. You have a table with columns: Product, Color, Price. You want to remove rows where both Product and Color are duplicates, but keep rows with same Product but different Color. How do you do this?

hard

A. Sort by Price and then remove duplicates.

B. Select all three columns in Remove Duplicates dialog and click OK.

C. Select only Product column in Remove Duplicates dialog and click OK.

D. Select only Product and Color columns in Remove Duplicates dialog and click OK.

Solution

1. Step 1: Identify which columns define duplicates

   Duplicates are rows where both Product and Color match.

2. Step 2: Select only Product and Color columns in Remove Duplicates

   This ensures rows with same Product but different Color stay.

3. Step 3: Confirm that Price is ignored in duplicate check

   Price differences won't affect duplicate removal.

4. Final Answer:

   Select only Product and Color columns in Remove Duplicates dialog and click OK. -> Option D

5. Quick Check:

   Choose columns defining duplicates to remove correctly [OK]

Hint: Select only columns that define duplicates before removing [OK]

Common Mistakes:

• Selecting all columns removes more rows than needed
• Selecting only Product removes rows with different colors
• Sorting does not remove duplicates