File Extensions — Set 5

Correct Answer: B. .docx

• **.docx** = the default Microsoft Word document format since Office 2007 — an Open XML file (internally a renamed ZIP archive of XML documents) that stores text, paragraph styles, images, tables, and track-changes data in a structured, interoperable format. • **Key fact** — .docx replaced the legacy binary .doc format to improve file compression, corruption recovery, and cross-application compatibility; a damaged .docx can often be partially repaired by unzipping it and editing the internal XML directly. • The format is an ISO standard (ISO/IEC 29500), which is why LibreOffice Writer, Google Docs, and Apple Pages can all open and edit .docx files natively without any conversion step. • 💡 Option A (.txt) is wrong because it stores only unformatted plain text with no styles, fonts, or embedded images; Option C (.xlsx) is wrong because it is the Microsoft Excel spreadsheet format, not a Word document; Option D (.pptx) is wrong because it is the Microsoft PowerPoint presentation format, not a Word document.

Correct Answer: B. .xlsx

• **.xlsx** = the default Microsoft Excel workbook format since Office 2007 — an Open XML file (a ZIP archive of XML documents) that stores worksheets, formulas, pivot tables, charts, and conditional formatting rules in a structured, portable layout. • **Key fact** — .xlsx replaced the legacy .xls binary format; because .xlsx is XML-based, damaged files can often be partially recovered by inspecting the unzipped XML content, and the format is readable by third-party tools without proprietary decoders. • The .xlsx format supports up to 1,048,576 rows and 16,384 columns per worksheet, far exceeding the 65,536-row limit of the old .xls binary format. • 💡 Option A (.xlsm) is wrong because it is the macro-enabled workbook format that supports VBA code execution, not the standard data-only workbook; Option C (.xltx) is wrong because it is an Excel template for generating new workbooks with preset layouts; Option D (.xlsb) is wrong because it stores data in binary format for faster performance, not in the standard Open XML structure.

Correct Answer: B. .pptx

• **.pptx** = the default Microsoft PowerPoint presentation format since Office 2007 — an Open XML file that stores slides, text, graphics, animations, transitions, audio, video, and speaker notes inside a ZIP archive of XML documents. • **Key fact** — .pptx replaced the legacy .ppt binary format as the ISO-standardized Open XML presentation format, enabling Google Slides, LibreOffice Impress, and Apple Keynote to open PowerPoint files natively without any conversion step. • Users can rename a .pptx file to .zip, extract its contents, and directly access embedded images or edit slide XML — a technique useful for bulk content extraction or automated slide generation. • 💡 Option A (.ppsx) is wrong because it is the slide-show-only format that skips editing view and opens directly in full-screen presentation mode; Option C (.potx) is wrong because it is a PowerPoint template for creating new presentations with preset slide designs and themes; Option D (.pptm) is wrong because it is the macro-enabled presentation format that supports embedded VBA automation code.

Correct Answer: A. .docm

• **.docm** = Microsoft Word Macro-Enabled Document — an Open XML file identical to .docx in structure but additionally permitted to store and execute VBA macros for automating repetitive tasks within the document. • **Key fact** — Microsoft deliberately separated macro-capable files (.docm) from standard files (.docx) so that opening a .docx guarantees no macro code can run, significantly reducing the risk of macro-based malware infections spread via documents. • Typical .docm use cases include automated form-filling templates, mail-merge scripts that generate dozens of personalised letters, and document-approval workflows triggered by embedded VBA buttons. • 💡 Option B (.docx) is wrong because it is the standard Word document format that explicitly cannot contain or execute macros; Option C (.dotx) is wrong because it is a macro-free Word template used for style and layout consistency; Option D (.doc) is wrong because it is the legacy binary Word format from Office 97-2003, predating the docm/docx security split.

Correct Answer: B. .xlsm

• **.xlsm** = Microsoft Excel Macro-Enabled Workbook — structurally identical to .xlsx but additionally permitted to store and execute VBA macros, making it the required save format for any workbook that contains automation code. • **Key fact** — when a user tries to save a macro-containing workbook as .xlsx, Excel warns that the VBA code will be permanently lost and prompts a switch to .xlsm, preventing silent destruction of automation scripts. • Finance and operations teams use .xlsm files for automated reporting dashboards, data-import buttons connected to external databases, and opening-event macros that refresh data as soon as the workbook loads. • 💡 Option A (.xlsx) is wrong because it is the standard macro-free workbook; saving macros to .xlsx strips the VBA code entirely; Option C (.xlsb) is wrong because it is the binary-format workbook optimized for faster load times with large datasets, not specifically a macro-enabling format; Option D (.xlam) is wrong because it is an Excel Add-in that extends Excel's global toolbar features, not a standard user workbook.

Correct Answer: A. .dotx

The.dotx extension is used specifically for Word templates. A template provides a pre-formatted structure for creating new documents. This ensures consistency in design across different files.

Correct Answer: C. .doc

The.doc extension was the standard format for Microsoft Word documents before 2007. It is a binary file format that stores document data in a single file. Modern versions of Word can still open and edit these legacy files.

Correct Answer: B. .ppsx

The.ppsx extension stands for a PowerPoint Slide Show. It bypasses the editing interface and starts the presentation immediately. This is useful for distributing final versions of a presentation.

Correct Answer: B. .accdb

The.accdb extension is the standard database format for Microsoft Access since the 2007 version. It replaced the older.mdb format used in previous versions. It supports advanced features like complex data types and attachments.

Correct Answer: B. .txt

The.txt extension represents a plain text file that contains no formatting. These files are universally readable by almost any text-editing software. It is a standard format for simple notes and data logs.