I have traveled thousands of miles but never moved.
I have told the stories of the world but have no voice.
What am I?

I can be written, spoken, broken, and made,
Yet I weigh nothing but shape every trade.
What am I?

The more you remove me, the more I grow,
Yet when you add to me, I shrink below.
What am I?

A word I know, six letters it contains,
Remove one letter and twelve remains.
What am I?

Step-by-Step Solution

Step 1: First Weighing

1. Divide the 12 coins into three groups:

   • Group A: 4 coins
   • Group B: 4 coins
   • Group C: 4 coins (set aside)

2. Weigh Group A against Group B.

Possible Outcomes:

• If the scale balances, the counterfeit coin is in Group C (the 4 coins not weighed).
• If the scale tilts, the counterfeit coin is among the 8 coins on the scale, and we now know whether it is heavier or lighter.

---

Step 2: Second Weighing

• Take three coins from the suspected group (either Group C if the first weighing balanced, or the tilting group if not).
• Weigh them against three known good coins.

Possible Outcomes:

1. If the scale balances, the counterfeit coin is the one left out.
   • Since we already know whether the fake is heavy or light from Step 1, we now have the answer.
2. If the scale tilts, we now know the counterfeit is one of the three being weighed and whether it is heavier or lighter.

---

Step 3: Third Weighing

• Take two of the remaining suspected coins and weigh them against each other.

Possible Outcomes:

• If the scale balances, the fake coin is the one left out.
• If the scale tilts, we know exactly which one is fake and whether it is heavier or lighter.

---

Final Answer:

👉 You can always find the counterfeit coin and determine if it’s heavier or lighter in exactly 3 weighings.

A man drives one mile at 30 mph.
How fast must he drive the second mile to average 60 mph for the total two-mile trip?

What comes once in a second, twice in a decade, but never in a century?

A man is running away from home.

• He turns left, runs straight, then turns left again.
• After his second turn, he sees two masked men waiting for him.

What is he doing?

A man lives on the 10th floor of an apartment building.
Every morning, he takes the elevator down to the ground floor to go to work.
However, when he comes home, he only takes the elevator up to the 7th floor and walks the rest of the way to the 10th floor.

Why does he do this?

A king gives you two jars and 100 marbles—50 white and 50 black. He will randomly select one jar, then pick one marble from it.

• If the marble is white, you win freedom.
• If the marble is black, you are executed.

How should you distribute the marbles to maximize your survival?