Brainstorming Puzzles Set 9 – Guess the Shirt Color | Crossing The Bridge | Counting The Pets

Logic is the art of thinking well: the mind, like the body, requires to be trained before it can use its powers in the most advantageous way

– Henry Home

Algorithmic thinking is really important as it enhances your thinking skills and can be nurtured with practice. (Refer the previous tutorial to know more about Algorithmic Thinking and try the puzzles before moving on to the solutions.)


 Solutions for the previous problems

Puzzle 8.1 Solution – Guess the Hat Color

Correct Answer:  The first and the second person are wearing hats of the same color whereas the third and fourth are wearing the unique color hats.

Explanation: Call the colors A, B and C

The people in line have these colors: ABCC

The last person sees “BCC” (two colors and a duplicate) so says “A”

The 2nd last person sees “CC”, so knows he is “B” since A is already worn by the last person.

The 3rd last person, using the logic that the two previous people must have seen duplicates surmises he has a duplicate of the last remaining color and says “C”.

The 4th last person applies similar logic and says “C”.


Puzzle 8.2 Solution – The secret Mail

Explanation: Ram sends the box with the lock to Shyam.

Shyam can’t open it but can put another lock on the box.

Shyam sends this box with the 2 locks back to Ram who unlocks his lock and sends it back to Shyam again.

So there is just Shyam’s lock on the box and Shyam can now open it.


Solving these puzzles is fun, isn’t it? So, wear your logic caps and get ready for your next brain workout:

Algorithmic Thinking
Algorithmic Thinking

Quiz 9.1  – Guess the Shirt Color

Mr. Red, Mr. Blue, and Mr. White meet for lunch in a restaurant. 
All of them are wearing either a red, blue, or white shirt.
Mr. Blue says, “Did you guys notice that all of us are wearing different colored shirts from our names?” 
The man wearing the white shirt says, “Wow, Mr. Blue, that’s right!”
Can you tell who is wearing what color shirt?

Just think about it and post your answer in the comments. I’ll explain this in the next tutorial.

Solution Added – Solution of “Guess the Shirt” puzzle


Quiz 9.2 – Crossing The Bridge

A bridge will collapse in 17 minutes.
4 people want to cross it before it will collapse. Only two people can cross the bridge at the same time and it’s a dark night so they need a torch. Since they only have a single torch, so one person needs to come back with the torch. Time taken by two people to cross the bridge is equal to the time taken by the slower one.

“A” takes a minute to cross.
“B” takes 2 minutes.
“C” takes 5
and “D” takes 10 minutes

How do they all cross before the bridge collapses?

Just think about the various scenarios and post your answer in the comments.

Solution Added – Solution of “Crossing the Bridge” puzzle


Quiz 9.3 – Count the Pets

In a joint family, everyone likes pets. In total, all except two pets are dogs, all except two pets are cats, and all except two pets are parrots.

How many of each pet are there in the family?

Just give this problem a thought and post your answer in the comments.

Solution Added – Solution of “Count the pets” puzzle


So start thinking and comment answer to the questions asked above and wait for the next post for the solutions.
Do Share and Subscribe and comment your opinion, queries and suggestions.
Keep Learning. Happy Learning 🙂 

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