A viral TikTok maths puzzle has left social media users scratching their heads – but we all know someone who can solve it
A mathematical brain teaser doing the rounds on social media has left countless people scratching their heads over its deceptively complex question.
Do you fancy yourself as a bit of a numbers whizz? While some might readily admit that mathematics isn’t exactly their cup of tea, others absolutely relish the challenge of cracking a demanding equation or working out percentages at lightning speed.
Whatever your mathematical prowess, tackling puzzles and brain teasers plays a vital role in keeping your mind sharp, and numerical problems provide an excellent workout for the grey matter, reports the Manchester Evening News. This particular mathematical mystery has been causing quite the stir, with some commenters confessing they find it so bewildering they “don’t even understand the question”, let alone how to solve it.
Fancy having a crack at a proper mental workout? Then see if you can get your head around this numerical riddle.
In a TikTok clip shared by Talk to the Nation, users found themselves completely stumped by what appeared to be a simple question, featuring a woman attempting to work it out. While she did manage to arrive at the right answer by the end of the video, numerous viewers remained utterly baffled by her method – with some unable to even comprehend what was being asked.
The puzzle was: “What is the 100th digit between 1 and 100?” At first glance, it might not seem particularly tricky, but it does demand some mathematical calculations to work out the correct digit. And for clarity, the solution isn’t as straightforward as “100”.
The puzzle is hunting for a particular digit, not a complete number. To clarify, the 10th digit is 1, while the 11th is 0 – these two digits combined make the number 10.
The lady in the video effortlessly cracked the puzzle, disclosing at the clip’s conclusion that she possesses a mathematics degree, explaining her numerical expertise. If you’re struggling to work out the solution, stop scrolling now, as we’re about to reveal it.
Answer
The 100th digit is 5, precisely, the initial 5 in the number 55.
This can be worked out using some maths and considerable logic. First, take away 9 from 100 to account for the single-digit numbers 1-9.
This gives you 91, which must then be divided by two since the remaining numbers 10-99 are all two-digit numbers, meaning each figure contains two digits.
After dividing 91 in half to get 45.5, add back the nine single digits, giving you 54.5. In the context of the puzzle, the additional 0.5 represents the first half of the following number, showing that the 100th digit is 5.