❓ Question of the day

For anyone who wants one small, real-world puzzle a day. No timer, no marks, nothing saved.

One question a day from the Workstation topics. Take your time: pick an answer, then read why every option is right or wrong. The wrong options are there because they're the mistakes people really make. A new question appears each day, and you can try the others whenever you like.

New questions are added from time to time.

All 14 questions

A shop's sheet has prices in E2 to E40. The owner types =SUM(E2:E40) in E41, then adds a new item in row 42. Why doesn't the total change?A. The sheet needs to be saved before it adds new numbersNot this one: Sheets recalculate straight away. Saving keeps your work but doesn't change any sums.B. Row 42 is outside the range E2 to E40Right: Right. The range stops at E40. Insert the new row inside the list (at any row from 3 to 40), so the range grows to include it, or change the range to include row 42.C. SUM only works for up to 39 numbersNot this one: SUM can add many thousands of cells. The limit here is the range that was typed.D. Row 42 needs to be bold to countNot this one: Formatting never changes what a formula adds up.

📖 Learn more: Office tools · Lesson 3: Let the sheet do the work: SUM, value and reorder warnings

A laptop has a 256 GB SSD with 5 GB free and 8 GB of RAM. It's slow even with only one app open. What is the most likely cause?A. Not enough RAM for one appNot this one: 8 GB of RAM is plenty for one app, so memory is unlikely to be the problem here.B. The screen brightness is too highNot this one: Brightness doesn't affect how fast the computer works.C. The processor is too old for one appNot this one: Even older processors handle one app; a nearly full drive is far more likely.D. The storage is nearly fullRight: Right. The operating system needs free storage for updates, temporary files and swap. Freeing space, starting with large unused files, usually helps.

📖 Learn more: Computer basics · Lesson 4: Why a computer slows down

You're in /home/asha. You type cd shop/letters and then cd ../... Where are you now?A. /home/ashaRight: Right. Each .. goes up one level: from letters to shop, then from shop back to /home/asha.B. /home/asha/shopNot this one: That's one level up from letters. ../.. goes up two levels.C. /homeNot this one: That would be three levels up from letters. ../.. goes up only two levels, which lands back at /home/asha.D. /Not this one: / is the very top of the computer, much further up than two levels.

📖 Learn more: Gentle Linux and the command line · Lesson 2: Finding your way: where am I, what's here, go there

A food-delivery app should assign each new order to the delivery rider who has been waiting longest. Which structure fits the waiting riders?A. A stack, so the rider who arrived last goes firstNot this one: That's unfair: the riders who arrived first would keep waiting while newer ones get orders.B. A tree, sorted by areaNot this one: A tree organises things inside other things. It doesn't decide who has waited longest.C. A queue of ridersRight: Right. First in, first out: riders join at the back and orders go to the front.D. A lookup from rider name to phone numberNot this one: A lookup finds one rider's details quickly, but doesn't keep track of who has waited longest.

📖 Learn more: Data structures in plain words · Lesson 2: Queues and stacks: who goes next?

The checkout page hides the "Apply discount" button for customers who aren't members. A non-member finds the button in the page's code and clicks it. What should stop them getting the discount?A. Hiding the button better, so it can't be foundNot this one: Anything sent to the customer's phone can be found and changed. Hiding is not a lock.B. Asking customers to promise they're membersNot this one: A promise isn't a check. The server must verify membership itself.C. The backend checking membership itselfRight: Right. The rule must live on the server, which checks who the customer is no matter what the page sends.D. Checking membership in the page's own code before showing the discountNot this one: Code on the customer's phone can be changed too. Only the server's check counts.

📖 Learn more: System design for builders · Lesson 1: The three main parts: front, back and the ledger

A job ad promises ₹80,000 a month for "simple typing work from home" and asks you to buy a ₹3,000 "starter kit" first. What's your best move?A. Don't pay, don't share documents, and report the adRight: Right. Genuine employers don't charge you to start work, and the pay is far too high for the job. Report it at cybercrime.gov.in or 1930.B. Pay, because the salary will quickly cover the kitNot this one: This is a well-known scam pattern. The salary never arrives, and the kit money is lost.C. Ask the company to take the kit money out of the first month's salary insteadNot this one: Paying out of your salary is still paying to get a job, and a fake company never pays a salary anyway.D. Pay half now and half after the first salaryNot this one: Any payment to get a job is a warning sign, however it's split.

📖 Learn more: Interview and job basics for AI-era builders · Lesson 3: Before the interview, and staying safe

You send a CV as a .docx, and the employer says the layout is "all over the place". What would most likely have prevented this?A. Using more spaces to line things upNot this one: Spaces are often the cause: they line up differently with different fonts and screens.B. Sending it as a screenshotNot this one: A screenshot can't be searched, copied or read by the employer's software, and it often looks blurry.C. Using a fancier fontNot this one: A font the employer doesn't have can make the layout worse, not better.D. Sending it as a PDFRight: Right. A PDF keeps the layout the same on every device. Keep the .docx for your own edits, and send it only if the employer asks for one.

📖 Learn more: Office tools · Lesson 4: A clear document: the notice and the supplier letter

Which password is strongest for your email account?A. Asha@1990, which mixes capitals, symbols and numbers as most websites askNot this one: It mixes characters, but a name and birth year are among the first things attackers try.B. mango-river-lantern-42Right: Right. A long phrase of unrelated words is hard to guess and easy to remember. Use it only for this account, so one leak can't unlock your others.C. P@ssw0rd!Not this one: Swapping letters for symbols in "password" is so common that attackers' lists already include it.D. qwerty123456Not this one: Keyboard patterns are among the most guessed passwords of all.

📖 Learn more: Computer basics · Lesson 5: Keep your computer healthy and safe

An AI suggests rm -rf ~/projects/old to free space. Before you run it, what is the most useful check?A. Look inside it with ls and back up what you needRight: Right. rm -rf deletes without asking and without a Recycle Bin, so look first and keep a copy of anything important.B. Add sudo so it definitely worksNot this one: sudo gives the command more power, which only makes a mistake worse. Your own folder doesn't need it.C. Run it twice to be sureNot this one: Running a delete twice does nothing useful, and doesn't make it any safer.D. Check that the internet connection is workingNot this one: rm works on your own computer and doesn't need the internet.

📖 Learn more: Gentle Linux and the command line · Lesson 3: Careful commands, and pasting from AI

A school stores students as a lookup with the student's first name as the key. Two students are both called "Aman". What goes wrong?A. The app keeps both, one under "Aman" and one under "Aman2", by itselfNot this one: A lookup doesn't rename keys on its own. It keeps one value per key.B. The second Aman replaces the firstRight: Right. First names aren't unique, so they make poor keys. Use a unique ID, such as a roll number, as the key.C. The lookup sorts them by surnameNot this one: A lookup doesn't sort, and doesn't look at surnames: the key is only the first name.D. The app refuses to save the second Aman and shows an errorNot this one: Most lookups simply overwrite without any warning, which is why the mistake is easy to miss.

📖 Learn more: Data structures in plain words · Lesson 3: Lookups and trees: find it fast, and things inside things

After a price cut, the shop's homepage still shows the old price, but the checkout shows the new one. What is the most likely cause?A. The database has two different pricesNot this one: The checkout reads the new price, so the database is already updated.B. The customer's phone is too oldNot this one: An old phone shows pages more slowly, but it shows the same prices as any other phone.C. The payment service changed the priceNot this one: Payment services charge what the shop sends them. They don't change the shop's displayed prices.D. The homepage comes from an old cached copyRight: Right. The homepage shows a saved copy. Refresh the cache whenever prices change, so every page shows the same price.

📖 Learn more: System design for builders · Lesson 2: Coping with a rush: the Diwali sale

The interviewer points to one function and asks how it works. AI wrote it and you've never read it closely. What is the best answer?A. Make up an explanation that sounds rightNot this one: If it's wrong, the interviewer will likely notice, and trust in everything else you say drops.B. Say you wrote it but have forgottenNot this one: That's untrue, and it suggests you don't know your own project.C. Say AI wrote it, then read it through with themRight: Right. Honesty plus working it out in front of them shows exactly the skill they're looking for: understanding code you didn't type.D. Change the subject to a part you know betterNot this one: Avoiding the question looks like hiding something. Interviewers usually come back to it.

📖 Learn more: Interview and job basics for AI-era builders · Lesson 2: Explain what you built, and your part in it

Someone types 5 kg in every cell of the Quantity column, and the SUM total shows 0. Why?A. The total cell is too narrowNot this one: A narrow cell shows ####, not 0.B. The total formula is missing the =Not this one: Without = the cell would show the formula's letters, not 0.C. The cells need to be in boldNot this one: Bold changes only how a cell looks. The problem is the letters in the cell.D. "5 kg" is text, not a numberRight: Right. Type only the number, 5, and put the unit in the column heading: "Quantity (kg)".

📖 Learn more: Office tools · Lesson 2: Your first spreadsheet: the stock sheet

Your new phone has a security update waiting. What's the wisest time to install it?A. Never, because updates always slow phones downNot this one: Security updates fix holes that criminals know about. Skipping them leaves the phone open to attack.B. Only after a year, when it's known to be safeNot this one: A year is a long time to leave a known security hole open.C. Soon, when it's charged and you can wait a few minutesRight: Right. Security updates close known holes, so install them promptly, ideally with a good charge and on Wi-Fi.D. Only if a friend's phone has had problemsNot this one: The update protects your phone whatever happens to anyone else's.

📖 Learn more: Computer basics · Lesson 5: Keep your computer healthy and safe