This is a classic riddle. Which weighs more?
Math Teasers are meant for thinking outside of the box. They require more logical thinking than being a math whiz-kid. Think creatively!
Actually, 16 ounces of feathers weigh more than one pound of gold.
This sounds like a trick, but it comes down to the two different measurement systems used for “common” items versus “precious metals.”
Feathers, like most groceries and household items, are measured using the Avoirdupois system.
Gold and other precious metals are measured in Troy weight. A “pound” of gold is significantly lighter than a standard pound.
Comparison Table
| Item | System | Mass in Grams |
| 16 oz. Feathers | Avoirdupois | 453.59g |
| 1 lb. Gold | Troy | 373.24g |
The Verdict: Even though 16 ounces sounds like it should equal one pound, the 16 ounces of feathers (Avoirdupois) outweigh the pound of gold (Troy) by about 80 grams.
Most “which weighs more” riddles rely on our brains jumping to conclusions about density or the specific way materials are measured.
Here are a few other classics that often trip people up:
This is the most famous version of the riddle.
The Trap: Your brain thinks of lead as “heavy” and feathers as “light.”
The Answer: They weigh the same. A pound is a pound, regardless of what the material is. The only difference is the volume—you would need a giant mountain of feathers to equal a small brick of lead.
The Trap: Because oil floats on water, people often assume it’s “lighter.”
The Answer: Again, one pound is one pound. However, because oil is less dense than water, one pound of oil will take up more space (volume) than one pound of water.
The Riddle: If a jar of honey weighs 2 pounds, and you eat half the honey, does it weigh 1 pound?
The Trap: Forgetting the weight of the container.
The Answer: No. It will weigh more than 1 pound because the glass jar itself has its own weight that doesn’t change just because the honey is gone.
The Riddle: Which weighs more: 10 kilograms of gold on Earth or 10 kilograms of gold on the Moon?
The Trap: Confusing mass with weight.
The Answer: The 10 kg on Earth weighs more. While the mass (the amount of matter) is identical in both places, weight is a measure of gravitational pull. Since Earth’s gravity is about six times stronger than the Moon’s, the gold on Earth would feel much heavier.
The Riddle: Which weighs more: A ship that is empty, or a ship that is filled with Styrofoam?
The Trap: Thinking Styrofoam is “weightless.”
The Answer: The ship filled with Styrofoam weighs more. Even though Styrofoam is incredibly light, it still has mass. Adding anything with mass to an empty vessel will increase the total weight.
Which of these measurement tricks do you find the most confusing?
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