Friday Funny: Clocks, Calculators and Lightbulbs algebra maths puzzle

David Meego - Click for blog homepageI have found another new numeric picture maths puzzle. Thanks goes to my good friend, Virginia, for inflicting this one on us.

I did get it wrong initially, so be warned… it does require a close look at the image to get the correct answer.

The puzzle image follows the standard format where it provides the answers to the first three equations, which should provide the information you need to solve the fourth equation.

Below is a poll for you to record your answer:

Please comment on how you went, but don’t give away the answer.


02-Oct-2020: Find the Solution here: Friday Funny: Solution to Clocks, Calculators and Lightbulbs algebra maths puzzle.

This article was originally posted on

5 thoughts on “Friday Funny: Clocks, Calculators and Lightbulbs algebra maths puzzle

  1. I had to use 2 assumptions :
    The first row has infinite solutions in R (2x + y = 21), so i made the assumption that there was a relationship between the image and the value
    I assumed that 3 lightbulbs stacked together represented the sum of ftheir values – in theory it could mean multiplicative or power relationships though.


      • Hi,
        I may have worded it badly, but i wasn’t ‘discounting the information shown on the clock faces’ – that’s what i meant when i said there must be ‘a relationship between the image and the value’ – i was trying to say that the clocks weren’t just random images, which would result in 2x+y=21, but that I needed to take note of the content in the image. By that I meant the 9pm and 3pm. Obviosuly i didn’t say it well! I guess I am not giving away the answer when I say I obtained 459 , which wasn’t the most popular answer (maybe a good sign!)
        Thanks for the challenge.I came across the challenge checking into one of your old stored procedures ‘spSearchOnAllDB’, which, like the first row in the puzzle, potentially has infinite uses.


      • Hi Guy

        You should check out the Resource Finder window in GP Power Tools build 28. It is using some of the spSearchOnAllDB functionality but is infinitely more powerful.



Please post feedback or comments

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.