Solving A Classic Interview Puzzle - Google Puzzle for Software Engineers

It's a classic google interview puzzle asked in the interviews for software engineers. The puzzle has four challenges. The idea behind this whole problem is to demonstrate how human mind can easily get conditioned.
This puzzle teaches you two lessons, so don't skip the video.

You can buy "Logically Yours" merchandise here:

Below are more google interview puzzles you can try:

Ant & Honey Puzzle || Increase your logical thinking

Google Interview Puzzle | Poisonous Milk Bottle | Simple yet Tricky

[suryasentosa]

It's true . After I found the answers of blocks A, B and C, then I started thinking complicatedly to solve the block D😂.
Thanks Mr. Ammar for your very interesting puzzles so far. I'm one of your fans.
Please upload more puzzles in YouTube channel 👍👍👍👏👏👏.

[numaanypervez]

I solved A, then B, then jumped to D 😁 and then started watching for C... it was lovely.

[TheCloudyoshi]

I couldn't get D, and somehow as soon as you started talking about conditioned thinking, I looked back at D and realized the solution before you showed the lines. Interesting video!

[avinashthakur]

Another solution to C could be similar to B.
As we divided B into 3 squares, further divide these 3 squares into 4 triangles(or squares).
Then you have 12 identical triangles(or squares)
Now, just group them into groups of 3 to get 4 groups.

This can form your solution also, or something different.

[vadimk]

For C you have also the option of drawing the diagonals of the 3 smaller whites squares-> 12 identical triangles and then easy to split into 4 🙂 you don't even need to think about the pattern of the others !!

[hemankgupta]

I actually solved all of them. C was a bit tricky but I figured it out. I appreciate the efforts that you put into making and animating these puzzles. Waiting for more new logic every week.👍👍👍❤❤❤

[Mr.Not_Sure]

0:31 A "identical and equal sized", but in author's solution they not identical. Rather symmetrical. But left and right shoe are not the same right?

[sreenath]

I'm a subscriber of some channels uploading critical thinking puzzles. Your channel is the best 🥰

[zacharymogel]

I knew for part D I could just draw 4 lines, but for C I thought of cutting it diagonally like A, then dividing those two parts in half again

[sushantkanojiya]

Great one. So happy that I almost solved the puzzle the same way. I guess, the conditioned mindset didn't affect me. I just went for the easiest solution. 😅

For the area C, there are 3 squares considering each square is of 1 cm² area. The total is 3 cm². Dividing by 4, it will be 0.75 cm² each. It's easy to divide outside squares by cutting the length of 0.75 cm . Now the remaining part, just draw the diagonal line, and it is divided into 2 identical areas of 0.75 cm² each.

But, your solution was amazing. It was all in front of our eyes, and we never observed. 😮

P.S.: Oh, it's so hard to explain the solution just by typing down here for me. 😅

[nowitspk]

went through all the 51 video. thanks for the playlist. I have a interview on tuesday will update how it went.

[algorithminc.]

Very nice. And quite important. Cheers.

[JandN]

I have another solution for C.
Make a diagonal cut from top left to bottom right and then bottom left to the corner of the inner square's bottom left point. Now you have 4 identical triangles.

[Klimbo]

Block C explanation of the thinking process strikes me as "pray for the solution to hit you in the face"
May I sugguest how I found it myself, using rather rational thoughts

1. Analysing lessons learned (pattern recognition)

When I saw the challenge of it, I tried to find some simpler problem which looked analogical. Block A had also a strange looking solution and I wondered what lesson learned I could get from that one on figuring out a procedure to methodically finding that strange morphologies.

I figured that if I considered the partition of the white region into the simplest equal parts, three squares, then any partition of them parts into equal subparts will give equal parts throuthoughy the whole zone too, as well potential to rearranging them into new assemblies if the same number of subparts.

In Block A, since I needed to divide by two, while I had three, I needed to divide the area into a common multiple of equal parts, six, then arranging the smaller partitions into assemblies of three, ie, two blocks of three equal parts.

The partition of the three equal squares into two pieces each turned to work out as 45º rectangles, which then arrenged into blocks of three would give the shape we sorted out intuitively.

2. Applying lesson learned

Applying this strategy, now we had the white zone of Block C separated into the three simplest equal partitions. Now, since we needed four and not three equal partitions, we need to find a common multiple, twelve. So each square must be fractioned into four equal elements.

I first tried breaking it into triangles again, but assemblies of three triangles don't really make for building elements. Then I tried a four square partition. Assemblying three squares into that L shape did allow to fill the white zone, and therefore the solution was found.

3. Comments
Mind I said "a common multiple", not the smallest one. If the shapes I found dividing the squares into the first order of partitions didn't give me any results, breaking down further into smaller sub-pieces with a factor of 2, 3, 4, etc, may have eventually solved the problem.

Thanks for reading!

[yaduvarma]

Haha... I actually solved D first, since that was the easiest... And then went on to solve A and B ... Unfortunately couldn't crack C...
Atleast I dodged conditioned mindset😋...

[dr.mohammedsuhail]

Hey ammar just came to know about your channel.. I am really happy to see that your channel has grown with soo many subscribers and views.... And content is just superb.... it reflects your hard work.. And no doubt the accent oration and confidence is showing reflection of your father and wisdom from your mom.... Subscribing now... ... Stay blessed.. All the best 🎉

[chriloaa]

In my opinion the solution of A is not correct or at least discussable. The to pieces have to same size but not the same shape. They can't be bring to a full coverage by only shifting within in the plain. A operation of flipping (or mirroring) has to be done to fulfill both requirements. I'm in doubt that this is allowed in this setup.

[ishandeshmukh]

For Solving C i tore the White region like A and flipped one piece to form a rectangle and then its easy to divide by 4

[LokeshSharma-hmjz]

LESSON 2 IS VERY USEFUL. It happens to me most of the times in coding quesitons

[levistepanian]

I solved C by imagining a diagonal cut similar to A, as well as a perpendicular cut strategically placed such that it divides each half into two equal pieces