Unlocking the Secrets to Solving the Riddle "A Man Steals $100 From a Store Register"

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As a lover of riddles and puzzles since childhood, few things delight me more than that "aha!" moment when the solution clicks into place. Riddles are a timeless way to stimulate our minds, dating back over 4,000 years to ancient cultures like Greece, China, India and more. Let‘s explore the origins of riddles, then work through solving the example riddle in the title together step-by-step. Get ready to flex your mental muscles!

A Puzzling Pastime for Millennia

Riddles have been traced back to the Sumerians in ancient Mesopotamia, with examples found in cuneiform writing over 4,000 years old! But cultures worldwide developed a tradition of challenging one another with brain teasers and unique logic puzzles.

In ancient Greece, riddles featured prominently in myths and legends. The most famous riddle originates from the myth of Oedipus, who had to answer the Riddle of the Sphinx to break a plague curse on the city of Thebes. The Sphinx demanded, "What walks on four feet in the morning, two in the afternoon, and three at night?" Oedipus solved it correctly: man, who crawls as a baby, walks upright as an adult, and uses a cane in old age.

Ancient Chinese scholars composed complex riddles using wordplay, homophones, dual meanings. Riddle competitions were held to identify top imperial scholars and civil servants through their intellectual prowess at solving puzzles.

In India‘s Vedic tradition, riddles called prahelikas were described as far back as the 4th century BC. They were seen as spiritual tools for developing consciousness and gaining wisdom.

The popularity of riddles has endured over millennia because they entertain our minds while sharpening critical thinking. Modern educators recognize riddles as excellent learning tools. Research shows riddles build skills in:

  • Logical reasoning
  • Identifying patterns
  • Deductive analysis
  • Lateral thinking
  • Abstract thinking
  • Drawing inferences based on incomplete information

Riddle-solving activates parts of the brain that control executive function, language, and visual imagery. The American Speech-Language-Hearing Association found classroom riddle activities improved reading comprehension among elementary schoolers.

But you don‘t need any special occasion to flex your mental muscles on some puzzles! Now let‘s put our heads together and walk through solving a classic riddle.

Introducing the Riddle

First, here is the riddle we will unlock:

"A man steals a $100 bill from a store‘s register. Then he buys $70 worth of goods at that store using the $100 bill, and gets $30 change. How much money did the store lose?"

Seems easy enough at first glance. But let‘s break it down step-by-step like detectives gathering all the clues to solve a theft case!

Dissecting the Riddle

Whenever I tackle a riddle, I like to methodically analyze each piece of information provided:

  • A man steals $100 from a store register
  • He uses that same $100 bill to buy $70 in goods from the same store
  • He receives $30 in change after buying the goods

The question asks how much the store lost total as a result of these transactions. To find the solution, we need to deconstruct each step and figure out how it affects the overall loss.

The Purloined $100 Bill

The first key fact is the man stole $100 from the register. So initially, the store is at a $100 loss from having that cash swiped. Now they are out $100 from their till.

Buying $70 of Merchandise

Next, we‘re told the man spends $70 of the stolen $100 to purchase goods at the same store. On the surface, it seems like the store recouped $70 of their money in the form of inventory. But in reality, they already lost the $100 bill itself when it was pinched from the register.

While they gained back $70 worth of goods, the actual $100 bill is still missing – essentially spent by the thief in exchange for the merchandise. So the store remains at a $100 cash loss.

Receiving $30 in Change

Finally, we learn the man receives $30 in change after buying the $70 of stuff. This means the store has now lost another $30 from its register by giving change back to the thief.

Tallying Up the Total

Let‘s recap each monetary gain or loss:

  • Store loses $100 from stolen cash

  • Gains $70 of inventory when thief buys goods

  • Loses original $100 bill used by thief

  • Loses additional $30 giving change to thief


  • Initial loss = $100
  • Additional loss from change = + $30
  • Total loss = $100 + $30 = $130

However, the store did regain $70 of value in merchandise. So the net loss is:

  • $130 total loss
    • $70 inventory gained
  • = $100 net loss

The total amount of money lost by the store is $100.

Explaining the Logic

Where the riddle becomes tricky is assuming the $70 of goods purchased comes off the total loss. In reality, the store is out the original $100 bill the moment it‘s stolen, so any transactions made by the thief using that money don‘t reduce the initial cash loss. The store just exchanges the stolen $100 for $70 of goods. But they‘re still out the $100 bill itself, plus the $30 lost in change.

The key is tracking each monetary transaction and not counting the $70 as a "gain" since the $100 bill itself was already lost initially. By breaking it down step-by-step, we can follow the logic to the solution!

Drawing It Out

For visual learners, it can also help to illustrate the monetary flows using a diagram:

[Insert diagram showing $100 stolen, then used to buy $70 goods, then $30 change given, equaling $100 total loss]

This makes it easy to see how the transactions flow through the stolen $100 bill, while the store remains $100 poorer in actual cash by the end.

Alternative Method

Here‘s another way to conceptualize the solution:

Let‘s imagine the man did NOT steal the $100, but came into the store with $100 fair and square to spend. In this case:

  • He spends $70 of his $100 on goods

  • He gets $30 change back

  • So he has paid $70 and gotten back $30 = $100.

  • The store has $70 of merchandise and $30 cash = $100 total.

No money has been lost!

But because the $100 was stolen, that original cash is missing from the register. So the store is still short the stolen $100 at the end, even though goods were bought with it.

More Riddles to Ponder

Now that we‘ve solved this riddle, let‘s apply these problem-solving strategies to a few more brain twisters:

Riddle: A clerk at a butcher shop stands five feet ten inches tall and wears size 13 sneakers. What does he weigh?

Riddle: I am lighter than air but a million men cannot lift me up. What am I?

Riddle: You are trapped in a room with no doors or windows. The only thing in the room is a wooden table. How do you escape?

Take some time to mull over the clues and see if you can determine the logical solutions. Share your thinking in the comments below!

Crafting the Perfect Riddles

As we‘ve seen, the key to a great riddle is including just enough contextual details to point to the answer, but requiring some clever logical leaps or lateral thinking to arrive there. Riddles help sharpen skills like:

  • Identifying essential information
  • Making inferences
  • Eliminating red herrings or false leads
  • Recognizing patterns and connections
  • Challenging assumptions
  • Thinking abstractly and spatially

There are some common formats and structures for crafting solid riddles:


Puns, double meanings, homophones, and figurative language can all be used to build riddles around wordplay. For example:

"What starts with E, ends with E, but only contains one letter?" (Envelope)


A metaphor states something is something else to hint at the answer. For example:

"What gets wetter the more it dries?" (A towel)


A rebus uses images or symbols to represent words and sounds. For example:

[image of eye] + [image of queue] = I Que (I seek)

Logic Puzzle

Like our example riddle, these brain teasers describe events, conditions, or steps that must be logically worked through.

Double Meaning

These riddles have one meaning on the surface, but a hidden second meaning is the real solution. For example:

"A man is found dead, lying in a field next to a rock. How did he die?"

He was playing chess with a friend and got beat (chess mate!).

As you practice more riddles, you‘ll start to recognize these patterns and can apply the appropriate solving strategies.

Helpful Hints for Riddle Mastery

Here are some tips and techniques I‘ve picked up over the years for becoming a riddle pro:

Break it Down

Methodically analyze each component. Look for any assumptions that should be challenged. Cover all possibilities.

Draw It Out

Illustrate the riddle visually if helpful. See if a diagram reveals any new insights.

Work Backwards

Start from the solution and work backwards to the conditions that would make it true.

Make Intentional Errors

Insert an incorrect assumption and follow it through to see if you get a contradiction. Then you know that assumption should be eliminated.

Sleep on It

Let your subconscious mull it over. Fresh eyes can produce creative insights.

Talk it Through

Verbalize your thinking. Feedback from others can reveal flaws or prompt realizations.

Rid the Redundancies

Cut out any unnecessary information to simplify the problem.

Wild Guesses are Welcome

Once logic fails, take some risks! You might luck out.

With these techniques in your mental toolbox, you‘ll become a riddle wizard in no time!

Riddles Unlock Our Full Potential

Beyond just being fun diversions, riddles provide great mental exercise throughout life. Recent research found regularly challenging your brain with problem-solving activities lowers the risk of cognitive decline and Alzheimer‘s disease.

But riddles aren‘t just for adults! Children can benefit greatly from practicing and mapping out solutions to riddles. Along with boosting cognitive skills, riddles help kids:

  • Improve listening and reading comprehension
  • Expand vocabulary and language mastery
  • Develop social skills through group discussion and problem-solving
  • Build confidence by tackling new intellectual challenges

For seniors especially, riddles provide engagement that enhances focus, memory, creativity and mental flexibility. I love whiling away the hours over coffee trying to best my retired friends with the latest riddles!

Truly, riddles are the perfect puzzle for all ages. It just takes some courage to open your mind, embrace the challenge, and put in the work to uncover the "aha" moment. But persisting through to the solution is immensely rewarding.

So grab some friends or family and put your heads together over these shared mental challenges. Let me know if you figure the riddles out before I do! Never stop nurturing your mind.


Written by Alexis Kestler

A female web designer and programmer - Now is a 36-year IT professional with over 15 years of experience living in NorCal. I enjoy keeping my feet wet in the world of technology through reading, working, and researching topics that pique my interest.