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You have two strings whose only known property is that when you light
one end of either string it takes exactly one hour to burn. The rate at
which the strings will burn is constant and strings are identical.
How do you measure 45 minutes?
That's how to measure 45 minutes!
What was the challenge?
1.
Burn both the ends of 1st string and 1 end of other string.
2. After 30 minutes, 1st string will be burnt out and half of the other string will be burnt out.So far we have counted 30 minutes.
3. Now burn the other end of 2nd end. It will take 15 minute to burnt out totally. This way, we have counted 30 + 15 = 45 minutes using 2 strings.
Mr. Yellow, Mr. Black and Mr. Brown, three best friends since
kindergarten meet in a function after 5 years. The three of them are
wearing either a Yellow, Black or Brown shirt.
After giving each other a friendly hug, Mr. Black says, "Hey, did you
notice that we are wearing a different colored shirt than our names!"
The man wearing a Brown shirt said, "Wow I certainly did not notice that but you are right Mr. Black."
Based on this conversation, can you find our who was wearing which colored shirt?
Know color of each person's shirt here!
Read this conversation first!
One thing is sure that Mr.Black is not wearing the BLACK shirt. He is also not wearing BROWN as well as we found the other person wearing the BROWN colored shirt is agreed with the statement made by Mr.BLACK in a conversation. So only color left is the YELLOW & Mr. Black must be wearing that.
Now, the colors left are BROWN and BLACK and persons left are Mr. Yellow and Mr.Brown. Since, each of them wearing different color than his surname, Mr. Brown must be wearing the BLACK shirt. And hence, Mr. Yellow is wearing the BROWN shirt!
To conclude, Mr.Black is wearing YELLOW shirt, Mr. Brown is wearing BLACK shirt & Mr. Yellow must be wearing BROWN shirt.
