Em Um Jardim Todas As Flores Menos Duas São Rosas - Em um jardim, todas as flores, menos duas, são rosas... | Matemática Genial
Em um jardim, todas as flores, menos duas, são rosas... | Matemática Genial

The Logic Behind the Classic Riddle

The riddle goes something like this: you walk into a garden, look around, and someone tells you "em um jardim todas as flores menos duas são rosas, todas menos duas são tulipas, e todas menos duas são margaridas." You're supposed to figure out how many flowers of each type are actually growing there. Most people overthink it immediately because the phrasing tricks them into assuming there's a hidden mathematical trick or some kind of botanical joke. It isn't one. It's a straightforward logic puzzle, and the reason it trips people up is that the grammar of "menos duas" does something subtle to how your brain parses the subject.

em um jardim todas as flores menos duas são rosas

Let me break down exactly what that sentence means in plain terms. When someone says "todas as flores menos duas são rosas," they are not saying "two of the roses are missing." They are saying "if you remove two flowers from the total count, the remaining ones are all roses." The same structure applies to the tulip and daisy statements. So you have three constraints acting on the same unknown set of flowers, and the task is to find a number distribution that satisfies all three simultaneously. Here's where the common mistake happens. People read "menos duas são rosas" and think it means "two are not roses," which is actually the correct interpretation, but then they get tangled because they start assigning variables like R for roses, T for tulips, D for daisies and write equations that don't account for the fact that these statements are about the complement of each category, not the category itself. Let me walk through the clean way to solve it.

Let F be the total number of flowers. The first statement says F minus 2 equals the number of roses. The second says F minus 2 equals the number of tulips. The third says F minus 2 equals the number of daisies. If we assume there are only these three types of flowers in the garden, then roses plus tulips plus daisies must equal F. That gives us the equation: (F - 2) + (F - 2) + (F - 2) = F. Simplify that and you get 3F - 6 = F, which means 2F = 6, so F = 3. Three flowers total. Each type appears exactly once. One rose, one tulip, one daisy. Check the logic against the original statements to make sure it holds. If there are 3 flowers and 1 is a rose, then "all except two are roses" means 3 minus 2 equals 1 rose. That works. Same for tulips and daisies. The puzzle is self-consistent and the answer is clean.

Why People Get Stuck On This

I've seen this riddle pop up in everything from interview questions to trivia nights, and the failure mode is almost always the same. Someone hears "todas menos duas" and their brain immediately tries to map it onto a visual scene where there are clearly many flowers and two are being excluded. They start imagining rows of roses with two non-rose flowers hiding somewhere in the background. The wording is deliberately vague about the total count, which is the whole point, but that vagueness acts as a cognitive trap. Another frequent error is treating each statement as independent rather than as three constraints on the same set. If you read them separately you might conclude there are infinitely many solutions. The key is recognizing that all three sentences describe the identical garden at the identical moment. You can't have one interpretation for the rose statement and a different interpretation for the tulip statement. They share variables.

👉 Clique no botão abaixo para saber mais sobre o assunto!

I once saw someone try to solve this by assuming the garden had roses, tulips, daisies, and at least one other flower type that wasn't mentioned. That's technically a valid reading of the text if you're being maximally literal, but it completely defeats the purpose of the riddle. The puzzle assumes a closed system with exactly three flower types. Without that assumption the problem is underspecified and unsolvable, which is worth noting because it comes up in discussions more often than you'd think.

Edge Cases and What Happens When the Constraints Break

There are scenarios where this riddle doesn't produce a clean integer answer, and understanding those helps you recognize when the puzzle has been modified or when someone is trying to trick you. For instance, if the statement said "todas menos uma são rosas" instead of "todas menos duas," you'd get the equation (F - 1) + (F - 1) + (F - 1) = F, which simplifies to 3F - 3 = F, meaning 2F = 3 and F = 1.5. Half a flower doesn't exist, so that version of the riddle has no valid solution in whole numbers. That's not a trick, it's just a broken constraint set. Similarly, if you add a fourth flower type while keeping the "menos duas" structure for all of them, the math changes. Four types would give you 4(F - 2) = F, which means 4F - 8 = F, so 3F = 8 and F = 8/3. Again, no valid solution. The riddle only works cleanly with exactly three types and the "menos duas" phrasing. This is the kind of boundary condition that separate solvers usually miss because they're focused on finding an answer rather than understanding why that answer exists.

The Broader Category This Riddle Belongs To

This isn't a unique puzzle. It falls under a family of constraint-satisfaction problems that show up in recreational mathematics, logic textbooks, and occasionally in entry-level computer science courses when teaching beginners about systems of equations. The underlying structure is the same regardless of whether you're talking about flowers, animals, or abstract objects. You have N categories, M constraints of the form "all except K belong to category X," and you need to find a distribution that satisfies every constraint simultaneously. The general solution approach is always the same: translate each natural language statement into an algebraic equation, recognize that the equations share variables, and solve the system. The trap is in the translation step. Natural language is ambiguous in ways that algebra is not, and "menos duas" can be misread as "including two" or "after removing two specific ones" depending on how lazily you parse it. I recommend always rewriting the statement in the form "total minus K equals count of category X" before doing any calculation. That simple reformatting alone prevents most errors.

There's also a useful related puzzle variant where the numbers change per statement, like "all except two are roses, all except three are tulips, and all except one are daisies." That version produces a different system of equations and a different answer, or possibly no solution at all depending on the numbers. I've used these variants in teaching settings to help students practice the translation step without getting comfortable enough to autopilot through it. The discomfort of slightly changed numbers is actually productive.

Practical Takeaway

If you're encountering this riddle in a context where someone expects you to solve it quickly, the fastest reliable path is to write down F = total, note that each statement gives you count = F - 2, sum the counts to equal F, and solve. It takes about ten seconds once you've done it a few times. The real value isn't in solving this particular instance but in recognizing the pattern so you can handle variations without second-guessing your interpretation of the wording.