[Genius if you can solve it?] Insight and intuition: a challenging IQ quiz

Because I work in dermatology

You might think, “Why dermatology when you should go to the dentist?” It says they go to a dermatology clinic, but that doesn’t mean they’re being seen as a patient—if they work there, of course they go every day.

5 yen

You might be tempted to say, “Subtract 100 from 110 and the answer is 10,” but if the pencil costs 10 yen, then the notebook, which is 100 yen more expensive, would be 110 yen, making the total 120 yen. It’s a problem that’s confusing precisely because the numbers are so neat.

Taro

Seeing that the eldest son is named “Ichirō” and the second son “Jirō,” you might expect the third son to be “Saburō,” but Tarō appears first—and there are four brothers. So the third son is Tarō.

cat's cradle

You might be inclined to think of people who build only large-scale structures, like carpenters or those in construction, right? But didn’t Tokyo Tower ring a bell? Suspension bridge, torii gate, and Tokyo Tower are all names of cat’s cradle techniques.

one time

When you imagine “99 - 1,” it looks like you could do it 99 times, but once you subtract 1 from 99 and it becomes 98, it no longer fits the premise of the question “How many times can you subtract 1 from 99?” It’s a slightly tricky quiz.

3 people

It’s tempting to reflexively think “7 − 3 = 4,” but in a game of hide-and-seek with seven people, one is the seeker. So there are six hiders to start; three are found, leaving three remaining.

Since it's a train, there is no smoke.

I bet some of you ended up picturing an SL (steam locomotive) running in your head while reading the problem statement. The specific speeds and directions served as a hook, making it a tricky question.