Skip to main content

Puzzle 55 - IOU

Harry owes Sam $30. Sam owes Phil $20. Phil owes Harry $50. Which of the following will settle the debts?


  1. Harry could give Phil $50.
  2. Sam could give Phil $20 and Harry could give Sam $40.
  3. Harry could give Phil $20 and Sam could give Phil $10.
  4. Sam and Phil could give Harry $50 total.
  5. Phil could give Harry $20 and could give Sam $10.

Solution: 5

 Harry owes Sam 30 and Sam owes Phil 20. We can say that Harry owes Phil 20. But Phil owes Harry 50. We can subtract 20 which Harry owes Phil. Which means Phil really owes Harry 30. But Harry owes 10 to Sam now (after subtracting 20 of Phil). So Phil can give this 10 to Sam on Harry's behalf and he can give the remaining 20 to Harry.

Popular posts from this blog

Puzzle 15 : All but two

Solution to puzzle 14 Huh, sending more money would have been much easier than this puzzle.      SEND     MORE   MONEY We have to find values for S,E,N,D,M,O,R,Y (8 digits out of 10).  Now, we're adding two 4-digits numbers.  Since 9999+9999 < 20000, M cannot be >=2. And by the "usual rules" for this kind of question, it can't be 0. So M=1 . Now, looking at the fourth (left-most) column, we have either S+1>=10 (if there's no carry) or 1+S+1>=10 (if there's carry). So S=8 or 9 , and O=0 or 1 . Since 1 is already taken, O=0   In the third column, we can't have E+0=N (no carry), so E+1=N and there's carry from the second column.   So in the second column either N+R=10+E=9+N, and R=9, or there's carry and 1+N+R=10+E=9+N, and R=8. So R=8 or 9 , just like S. IF S=8 and R=9,we're looking at 8END + 109E ====== 10NEY But this cannot possibly work: we need to get either E+0=10+N or 1+E+0=10+N i...
Read more

Puzzle 47

  Solution: First and last chests have treasure in them. Explanation : Message 1 says that middle chest has treasure. Since all messages are false, middle chest has no treasre. Message 2 says that all these chests have treasure. Which means at least one of them does not have treasure (and has poison). Which is middle chest. Message 3 says that only one of the chests has treasure. As this is false, more than one of the chests have treasure. As middle one has no treasure, the other two - first and last have treasure.
Read more

Puzzle 19 : Water, water everywhere

 I know I have been greatly missed all this time. ;) Any ways, let us have some more fun with numbers and logic.  Water, water everywhere   This is an interesting puzzle from the website mathisfun. The cold tap in my bath lets the water in at the rate of 15 litres per minute. The hot tap fills the bath at the rate of 10 liters per minute. The plug hole lets the water out of the bath at the rate of 12 liters per minute. The bath holds a maximum of 520 liters. I turn both taps on, but forget to put the plug in. How many minutes does it take for the bath to overflow? Let me reiterate the statement by the original author here. Don't try this at home. Water is precious. Find the solution here
Read more