Solved in 2 mins. Started with 7 for the last square as common for 21 and 56. Then last row 2x4x7 ( 4 in the center as the large number - 180 in the center). Then last column 1x3x7 for 21 (3 in center as larger number -120 in center) Then it was easy 6x9x1 for 54.
It took me about 5 minutes to solve it. Seeing as only one of the products was odd, I worked out what 3 numbers could combine to form it. I then figured 9 would need to be involved in one of the bigger if not the biggest product. Then factoring.👍
I was so excited I got started without keeping track of the time haha. 8 minutes at most, but I'd estimate 5-6 minutes. I did it in my head without paper, though I will say I began with the 21 column instead of finding where 5 was located. I solved it like so: 21 is only divisible by 2 prime factors, meaning the 3 numbers present must be 3, 7, and 1. I then moved onto 54, which had to have a 9 in it. 54/9=6, so the other numbers are either 6 and 1 or 2 and 3. Due to the current ambiguity of the 21 column, we need more information. From here, I also noticed that the 5 had to be in the row and column involving numbers with the number 0 in the ones column. 180/5=36, and that means that the 180 column needed the 9. That means 180 column is 9, 5, 4. 120/5=24, so let's see if 1, 3, or 7 fits there. 24 is not divisible by 7, and 1 would be invalid because 120/5/1 does not equal a 1-digit number. That means it has to be 3, meaning that the other number is 8. The 120 row is 8, 5, 3. 54 is not divisible by 7, meaning that 1 has to go in the 54 row. 54/9=6, meaning that the 54 row is 6, 9, 1, and the 21 column is 1, 3, and 7. By process of elimination, the missing digit on the bottom left is 2. This means that the numbers are, left-to-right, top-to-bottom, is: 6, 9, 1, 8, 5, 3, 2, 4, 7.
I have been teaching my 5th grade grand daughter how to do these. I found easiest way to teach her is to have her create these puzzles for me to solve so that she understands the mechanics.
Solved in less than 2 Minutes, but with a pen and paper. The short time to solve, is extracted from the decision, where to start from. Nice problem. Thanks.
Within 2 mins 3rd column , chose 21 ,7*3*1 Then 3rd row With 7*4*2 Then put 5 in the mid Then found the left 4 numbers 8*5*3 fit for the second row Then made the remaining possibilities
2 minutes, no notes. Started with 5 in the middle because of the 180 and 120 and worked it out from there. The hardest part was remembering where I had placed the numbers.
Forgot to track the time, a few minutes. Would have been way faster with a pencil, I almost immediately got the idea but I'm not good at keeping track of a bunch of numbers in my head so I took a bunch of time to make sure I didn't just immediately forget what I just figured out again.
find the prime factors we get 2,3,5, 7,easy to place 7 at the intersection of 21 & 56; 5 is prime factor for 120 and 180 hence goes in the center intersection . rest can be easily worked out
I solved it without using the rule "use all the numbers 1-9" (because i paused it before the rule came up) I came up with a different answer but i think its harder that way. The rule just helps you narrow down the answer
Solved in 2 mins. I first placed 9. Since 180 and 54 are multiples of 9 , no other no is multiple of 9. Then find position of 5 accordingly to it as 120 and 180 are multiple of 5. Then 4 left in second column to make 180. To make 56 and 21 , 7 will be placed in 3 row n last column. So 2 left in last row to make it 56 and 3 and 1 will be placed in 2nd n 3rd to make it 21. Placed 3 in second row n 1 in first row. Finally 6 and 8 left to make it 54 and 120.
Took ~30 sec Start with 21. As 3*7 = 21, position of 7 is known, and so is 3 and 1. Now we know the places of 9 and 6 too, as 96 isn't divisible by 9. Then it gives us 5 and 4 for making the number 180. Rest 8 and 2 would complete the set
actually initially i thought its difficult but able to solve it easily (within 1min- 30 sec ) however it was little difficult for me to remember mentally
1-2 mins for me. 3rd column = 1×3×7 by default. 2nd column = 4×5×9 by default. 1st column = 2×6×8 default. Since 120 and 180 are the only multiples of 5, thus 5 is in the center. 2nd row = 8×5×3 by default. 1st row = 6×9×1 by default. 3rd row = 2×4×7 by default.
Don't feel bad. These take practice. I am an RN. I can solve it in 5 minute, but I need pencil and paper to do it in that short of time to keep track of what numbers that I have already used. It's logic not math skill.
Hardest thing here is to keep track of the numbers in your mind, but that's a great mind exercise.
Thank you for this!
Amen on that!
Solved in mind: YES
Time: 3 min .... not bad :)
Same :)
Took me less than a minute to solve in mind.
Solved in 2 mins. Started with 7 for the last square as common for 21 and 56. Then last row 2x4x7 ( 4 in the center as the large number - 180 in the center). Then last column 1x3x7 for 21 (3 in center as larger number -120 in center) Then it was easy 6x9x1 for 54.
Brilliant !! That was fast
I did mine a little differently. 2x4x7 =56
8x5x3= 120. And 6x9x1=54
Thank you for the brain teaser.😊🇺🇲🪶
I also used same approach but I took 5 min
It took me about 5 minutes to solve it. Seeing as only one of the products was odd, I worked out what 3 numbers could combine to form it. I then figured 9 would need to be involved in one of the bigger if not the biggest product. Then factoring.👍
I was so excited I got started without keeping track of the time haha. 8 minutes at most, but I'd estimate 5-6 minutes. I did it in my head without paper, though I will say I began with the 21 column instead of finding where 5 was located. I solved it like so:
21 is only divisible by 2 prime factors, meaning the 3 numbers present must be 3, 7, and 1. I then moved onto 54, which had to have a 9 in it. 54/9=6, so the other numbers are either 6 and 1 or 2 and 3. Due to the current ambiguity of the 21 column, we need more information. From here, I also noticed that the 5 had to be in the row and column involving numbers with the number 0 in the ones column. 180/5=36, and that means that the 180 column needed the 9. That means 180 column is 9, 5, 4.
120/5=24, so let's see if 1, 3, or 7 fits there. 24 is not divisible by 7, and 1 would be invalid because 120/5/1 does not equal a 1-digit number. That means it has to be 3, meaning that the other number is 8. The 120 row is 8, 5, 3.
54 is not divisible by 7, meaning that 1 has to go in the 54 row. 54/9=6, meaning that the 54 row is 6, 9, 1, and the 21 column is 1, 3, and 7. By process of elimination, the missing digit on the bottom left is 2. This means that the numbers are, left-to-right, top-to-bottom, is: 6, 9, 1, 8, 5, 3, 2, 4, 7.
I really appreciate your honest reply… and it was almost similar approach… fantastic :)
I have been teaching my 5th grade grand daughter how to do these. I found easiest way to teach her is to have her create these puzzles for me to solve so that she understands the mechanics.
Solved in less than 2 Minutes, but with a pen and paper.
The short time to solve, is extracted from the decision, where to start from.
Nice problem. Thanks.
Within 2 mins
3rd column , chose 21 ,7*3*1
Then 3rd row
With 7*4*2
Then put 5 in the mid
Then found the left 4 numbers
8*5*3 fit for the second row
Then made the remaining possibilities
2 minutes, no notes. Started with 5 in the middle because of the 180 and 120 and worked it out from there. The hardest part was remembering where I had placed the numbers.
2 mins in mind.. 21 made it quite easy
Forgot to track the time, a few minutes. Would have been way faster with a pencil, I almost immediately got the idea but I'm not good at keeping track of a bunch of numbers in my head so I took a bunch of time to make sure I didn't just immediately forget what I just figured out again.
find the prime factors we get 2,3,5, 7,easy to place 7 at the intersection of 21 & 56; 5 is prime factor for 120 and 180 hence goes in the center intersection . rest can be easily worked out
Amazing! 👏👏👏
I solved it without using the rule "use all the numbers 1-9" (because i paused it before the rule came up)
I came up with a different answer but i think its harder that way. The rule just helps you narrow down the answer
It took me 5 minutes to solve it without pen and paper , because I started wrong I filled the first row with (2×9×3)
But it didn't work out ;)
It took me 4-5 minutes to solve but coincidentally my approach was exactly the same as yours, even the order of filling the boxes was same
I sloved within 4 minutes ! I used least common multiple method 🙌
Solved in 2 mins. I first placed 9. Since 180 and 54 are multiples of 9 , no other no is multiple of 9. Then find position of 5 accordingly to it as 120 and 180 are multiple of 5. Then 4 left in second column to make 180. To make 56 and 21 , 7 will be placed in 3 row n last column. So 2 left in last row to make it 56 and 3 and 1 will be placed in 2nd n 3rd to make it 21. Placed 3 in second row n 1 in first row. Finally 6 and 8 left to make it 54 and 120.
It took me around 30 seconds to solve, but if someone would have asked me for an explanation at the same time then i would have confused myself!
Solved in literally like under a minute .. maybe got lucky this time… started with 1 row and the same column so yeah did that under a minute
I took a few minutes to solve this without paper, but I'm not sure that I would describe the puzzle as "easy." It's just doable.
Easy meaning the logic behind it is simple. Mental calculation is the hard part, but it has nothing to do with logical reasoning.
3 minutes, first I solved 21 row(1,3,7), then 56 row(2,4,7), and just 5,6, 8, 9 to put in first square, from second try I have ordered them as well
Took ~30 sec
Start with 21. As 3*7 = 21, position of 7 is known, and so is 3 and 1. Now we know the places of 9 and 6 too, as 96 isn't divisible by 9. Then it gives us 5 and 4 for making the number 180. Rest 8 and 2 would complete the set
Completed in 4 min, starting with 7, and then fixed the position of 3 and 1.
30 Seconds. Done.
Lovely!!
actually initially i thought its difficult but able to solve it easily (within 1min- 30 sec ) however it was little difficult for me to remember mentally
@3:04 nice
I solved it . In first row 6,3,3.
In 2nd row 2,60,1.
In 3rd row 8,1,7.
😂
Honestly , I was able to solve the puzzle in just 1 min 😊🙏 that was great 😃👍
1-2 mins for me.
3rd column = 1×3×7 by default.
2nd column = 4×5×9 by default.
1st column = 2×6×8 default.
Since 120 and 180 are the only multiples of 5, thus 5 is in the center.
2nd row = 8×5×3 by default.
1st row = 6×9×1 by default.
3rd row = 2×4×7 by default.
Good approach!!
first thing i noticed is the seven then thought about the rest for 5min
Lovely :)
5 min... Not bad
This was easy. Took about a minute.
Solved in mind: Yes
Time took: 5 min 12sec
Almost 40 seconds
That was lightening fast.. :)
Easy with paper, Strengthens fundamental of first principle.
7, 5, and 9 can only fit in specific squares. Then, work out squares for 1 and 3 and rest is easy.
that was fun. thx.
I used a cronometer: 10min45s without any assistance 😁
21 column 1st about 6 min
Time : 3 min 28 secs
solving was the easy part keeping track of where i put which number was hard 😂
nicee puzzle.
Haha.. true :)
I applied my number knowledge of 'common factors.'
I did it in 41 sec
I think playing chess blind folded does help visual retention in mind
Solved it in three minutes
Same here:)
I was able to solve in 3 minutes.
Me too :)
I play Mathdoku regularly.
It took me only 10seconds
Thanks Nimesh for bringing this puzzle game to my notice. It deserves a dedicated video.
Solved in 1st attempt below 1 mins
21 = 7×3
56 = 8×7
Same here. Surprised to see so many people solving it in more than one minute. I feel proud 😁.
Even with pen and paper I couldn't solve the problem. By the way I am an investor and a millionaire. 🙂😊❤️
Don't feel bad. These take practice. I am an RN. I can solve it in 5 minute, but I need pencil and paper to do it in that short of time to keep track of what numbers that I have already used. It's logic not math skill.
2 9 3
12 10 1
4 2 7
I started with a 10 in the middle since 120 and 180 and it seems alright this solution as well
Solved in 3 minutes 40 seconds.
3 minutes
1st row 3 18 1
2nd row 4 10 3
3rd row 8 1 7
Solved! 4 mins
Excellent!
Solve by 9*5*4=180
All got in less than 1 minute
Can anyone try solving this puzzle with coding ?
I tried to code but I'm unable to think of the proper algorithm
Took me 5 minutes to solve
9min for me
I took 10 min
1min
3-4 mins.
Just in mind its impossible.Took 2 minutes using pen and paper..
Glad to see you didn’t give up! That’s important of all.
Just 1 minute.
Just under 3 minutes
There is one more solution
Order of logic 7 3 1 2 4 5 9 6 8
6 9 1
8 5 3
2 4 7
Solved in 2 mins...Started with 21.
.Since 21 = 7*3*1....Then the Whole Thing will Follow then...
691 | 853 | 247
I also started with 21. I always knock out combinations that use up prime numbers first.
6 9 1
8 5 3
2 4 7