You’ll need a sharp mind to solve this baffling quiz question.
Pub quizzes can be good fun, no matter how in-depth your general knowledge is. You might be someone who can breeze through the questions and always come out on top, or you might just be there for a good time with your mates even if you get every question wrong.
The questions asked in a pub quiz normally fall into different categories, such as sport, film, and history, but they can also mix things up with more riddle or brainteaser-based questions that challenge you to think differently to come up with an answer. And one of these questions is said to be so tricky that it “caused war” at a pub quiz many years ago.
In a video on TikTok, radio presenter Rob Gormley posed the pub quiz question he “still uses to this day to annoy people”.
He said he first heard the question “some years ago” when it caused “ructions” as people were convinced they had the right answer – despite many of them being incorrect.
The question was: “A builder builds 100 houses. The last thing the builder has to do is put numbers on the doors. They’re numbered 1 to 100 – it’s not a trick question. 100 houses, he needs numbers from 1 to 100. How many number 7s is the builder going to need?”
It might seem simple enough, but many people make the same mistake when trying to answer the question. Think very carefully about how many times the number 7 appears in the numbers 1 to 100, and when you think you’ve got the answer, scroll down to see the solution.
The correct answer is actually 20. There’s no trick to this question, but there’s still a common mistake that a lot of people make. When you count the numbers, it’s easy to just jump to all of the ones ending in seven – 17, 27, 37, etc. If you remember that 77 needs two sevens, then this method brings you to 11, which is what many people in the comments answered.
However, that’s not the right answer as you’ve forgotten something important – all the numbers starting with seven. There are 10 numbers that start with a seven, 70 through to 79. Some people answered 19 as the total, but they also forgot the second seven in 77. So, with all the numbers starting and ending in seven accounted for, the answer is 20.
In the comments, one person said: “20. Worked it out before you finished speaking. Very simple logic and worrying that people argued about it.” Another added: “I was SO SMUG that I counted both the sevens in 77 before I realised (too late) my answer was still mega wrong.”
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