Nov 22, 2006
Pattern Recognition Brain Teaser
By: Caroline Latham
Here’s a puzzle to test your ability to find a pattern and test it against more data.
In this table, each row across follows the same pattern of numbers. See if you can discern the pattern and fill in the missing number in the bottom row. For added challenge (or competition), time how long it takes you to complete the puzzle. Then, pass it along to someone else and see if they can solve it faster. The slower one has to cook dinner!
| 7 | 4 | 8 |
|---|---|---|
| 3 | 9 | 7 |
| 6 | 5 | 10 |
| ? | 8 | 4 |
Executive functions, like planning, and spatial processing are handled by your frontal lobes.
Have you solved it yet? If not, here’s a hint:
If you read your figures like words in the West,
then multiply your efforts and subtract the rest.
Keep reading for the answer and solution.
(7x4)-8 = 20
(3x9)-7 = 20
(3x8)-4 = 20
The answer is 3.
[…] Click Pattern Recognition Brain Teaser for the answer and solution. […]
Sigh! Could not get this teaser either. However, I did get the clue (somewhat). But what I found interesting is when I did repeat mentally the explanation, my brain felt, how can I say, a sense of wellbeing, like it was being nourished. Are all brain teasers not created equal in this regard? I remember mental distress after doing other ‘brain teasers’ years back.
Hi Michelle, you are probably experiencing the release of dopamine and other neurotransmitters that create that sense of wellbeing as you identified a pattern. Which is why learning, brain teasers, trading successfully, and other “brain exercise” activities can be quite addictive!
A different application, but illuminating
http://www.sharpbrains.com/blog/2006/10/13/the-joy-of-giving-and-the-cognitive-and-emotional-health-project-the-healthy-brain/
Looked at the problem differently. I didn’t get your solution…but I had fun. I said 7+4+8=19
3+9+7+19
6+5+10=21
9+4+8=21
In trying to make a second “pair” that were equal I put 9 in your empty spot.
Well…I’v always been bad at math and any form of logic. But I had fun!
OOOPS…I can’t type either.
3+9+7=19 also “I’ve”
Maryanne,
While the dopamine rush that Alvaro mentions above happens when you solve the puzzle or understand the answer (the “aha!” moment), working through the puzzle is good brain exercise in and of itself (you’re getting challenging and novel mental stimulation). And you did your math correctly with a logical pattern, so you’re not that bad at either task! The typos … well those may be more due to a lapse in attention and hand-eye coordination. Keep working and having fun with it!
came up with something different, in terms of a relationship. subtract each number from 9, take the absolute value of this difference, and sum them, the total is always 8 ie. 7–9=-2=2 (absolute), 4–9=-5=5, 8–9=-1=1 so 2+5+1=8
similarly in the second and third rows, sum is 8. therefore the number in the fourth row can be either 7 or 11.
convoluted solution and non-unique.
wonder what that says abt my brain!
You’re right, that does follow a pattern! Both you and Maryanne are finding creative solutions, which is good exercise for your brain! I think it says that your frontal lobes are in good shape — good work!
[…] 6. What’s the missing number: Pattern Recognition Brain Teaser […]
This clue confused me:
If you do your figures from east to west,
wouldn’t that mean from right to left?
Goodness Randy — you’re right! I’ll change it now!
[…] 6. What’s the missing number: Pattern Recognition Brain Teaser […]
An alternate solution, since the problem doesn’t state that the numbers must be integers:
If the first number is greater than the second number, add them and then subtract the difference of the first and second number. This covers row 1 and row 3.
If the first number is less than the second number, then add them and then subtract one less than the difference. This covers row 2, and indicates 2.5 as a solution to row 4.
Joseph,
Interesting solution, but if you don’t know what the first number in line 4 is, how do you know which rule to follow (the rule for lines 1 & 3 or the rule for line 2)?
Caroline,
Luckily for me, there was no solution where the first number is greater than the second number.
Joseph,
You’re right. The solution for the first number being larger doesn’t make sense (I end up with 16=4). If the first number is smaller, it does work out, but I get 1.5 as an answer.
x+8-(8-x-1)=4
x+8–8+x+1=4
2x+1=4
2x=3
x=1.5
Nice solution! Complicated, but it works!
Caroline,
Right you are! Thanks for the correction.
1
11
21
1211
111221
312211
? whats next
perhaps
13112221?
good one!
i found a different solution
7*4=2 8
3*9=2 7
6*5=3 0, the important digit is only the last digit therefore
3*8=2 4, now 6 may have worked but each pair has an odd and an even number plus no pair is double digit.
Creative Michael! Following your rules, I get 3 and 8 as possible answers, without a way to choose one answer. In line 2, both 3 and 9 are odd, so keeping it even and odd in each line doesn’t work. If you can come up with another rule to make only one answer, it’ll work!
[…] 6. What’s the missing number: Pattern Recognition Brain Teaser […]
I didn’t get the correct answer. I got five. the way I came to this was by adding the first and third number in each row. then you take that answer and subtract 1 from the number in the “one’s” spot. excuse my lack of knowledge. the number 123 1 is the hundreds, 2 is the tens, and 3 is the ones. so subtract 1 from the ones place and I came to the answer 5.
[…] 14. What’s the missing number: Pattern Recognition Brain Teaser. […]
I came up with 3 but I got it in a different manner. Here is the way I figured it out.
1. 7 x 4 = 28 and Subtract first number = 8
2. 3 x 9 = 27 and subtract the first number = 7.
3. 6 x 5 = 30 and subtract first number but since number can’t be zero make it 10.
4. 3 x 8 = 24 and subtract the first number = 4.
Although the 3rd rule doesn’t jive all that well it still works.
[…] Pattern Recognition Brain Teaser […]
Pattern Recognition …C is the answer I picked.
i came up with
(7×4)-20 = 8
(3×9)-20 = 7
(5x6)-20 = 10
(3x8)-20 = 4
go figure..
dorks.
Hello Erin, I wish you the best in 2008, perhaps including a more willing attitude to take on challenges and, if you decide not to give it a try, not to insult other people in that defensive, unhelpful way. No one is perfect
Have a great holiday and we hope to see you around again.
I thought the exact same way as Michael, and icansure:
1. 7 x 4 = 28 and Subtract first number = 8
2. 3 x 9 = 27 and subtract the first number = 7.
3. 6 x 5 = 30 and subtract first number but since number can’t be zero make it 10.
4. 3 x 8 = 24 and subtract the first number = 4.
I think 7 lol
cyaa xx (i just guessed btw) haah! x
Blast! Why was the solution at the bottom of the page? I glanced at it before I had a chance to attempt the puzzle. Why not make it so you have to click to find the solution so you don’t accidentally see it?
Yay, I got 3 also. I’m not usually amazing with math, so I’m very surprised that I got it. But I solved it the exact same way as icanrule. Great minds think alike, I suppose
Oh, and, as a random addition, I found another pattern. In the 1st and 3rd lines, the middle number is the lowest number, while the outside two are higher, and lines 2 and 4 are the opposite. That’s the first pattern I was trying to follow.
i have streets but no pavements i have cities but no buildings i have forrests but no trees i have rivers yet no water what am i
johnboy: you are a map that knows how to use a computer.
1
2
3
4
5
? what’s next?
7 comes next; you are listing prime numbers and perfect squares in numerical order.
This visual-spatial reasoning question is similar to those that appear in the UMAT.
64, 5, –34, 654, 1, 871, –11, .… What comes next?
I found another (awkward)pattern. If you add the two outside numbers from each row, subtract 1 from the sum and lastly pick the ending digit of the number, that would be your numerical value in the middle. If you limit the numerical variables to single digit numbers then the number to the left in the last row would have been five. E.g.-
7+8=15–1=14 (four)
3+7=10–1=9 (nine)
6+10=16–1=15 (five) and lastly you would have
x+4–1=8, your answer would be 5,
0… What comes next?