# This Riddle Is As Easy As ABC, but Most Can’t Crack It on Their First Try. Can You?

July 9, 2019 Updated: July 9, 2019

Riddles may seem like a silly past-time, but there’s a lot of scientific evidence to suggest that simple brain-training activities can help keep the mind sharp into old age, reducing the risk of dementia over the long term! So doing puzzles isn’t just a way to kill time; it’s a way to train your brain.

Today, we have a logic challenge that will stump most adults! And it’s as simple as you could possibly imagine.

One way to remember the months of the year and the number of days they each have is to use your knuckles. Start by making fists with your hands and put them in front of you. Starting with the left, you count January, the first month, from the left pinky knuckle.

Don’t count your thumbs, which you should tuck inside your fist, or anything else except the knuckles and grooves. January has 31 days, as do all the other months that fall on the knuckles.

You’ll notice that the months that fall in the grooves only have 30 days (with the  exception of February). You’ll also see that the knuckles on your left and right index fingers touch.

This shows you that July and August both have 31 days.

Do you remember learning about the calendar at school? Many people learned the common mnemonic device: “Thirty days has September, April, June, and November. February has 28 alone, And all the rest have 31.” So the answer is simple, right? Just one. But hold on a minute?

But February is always confusing. How do you know when it has 28 and when it has 29? There’s a great way to remember when it’s a leap year, which could also help us solve our puzzle.

The problem is the actual solar year is a little bit over 365 days (365 days, 5 hours, 48 minutes, and 45 seconds, to be exact), so if we didn’t have leap years to help us catch up, we would end up “losing” a considerable chunk over time! In order to avoid this, we have the 29-day February every four years.

But for a quick rule of thumb, there’s an easy way to check if any given year is a leap year.

1. The year can be evenly divided by 4
2. If the year can be evenly divided by 100, it is NOT a leap year, unless
3. the year is also evenly divisible by 400. Then it is a leap year.

So for example, 2019 can’t be divided by 4, 100, or 400, so we know it isn’t a leap year. What about 2020? Well, it can be divided by 4, so it’s a leap year! Back to our problem: knowing that February has 28 days every three years out of four doesn’t solve it either.

So, the answer is one, but what else could it be? Look again at the wording of the riddle. Do you notice the words “only” or “just”? Nowhere to be seen, are they?

This means you need to count any and every month that has 28 days. Which are … all of them! In fact, the correct answer is 12.

All 12 months have at least 28 days, it’s just that 11 of them have a couple or a few more. Feeling a little sheepish? Don’t worry, most people have trouble with this puzzle.

Our brains are often trained to look for the thing that’s different rather than seeing the commonalities between a whole set of things. Share this simple riddle with your kids, friends, and family. See how they do!

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