Science reading passage exploring the evidence for life on Mars, including NASA missions and Viking lander findings.

The image you've uploaded contains a logic puzzle titled "Is There Life on Mars?". Let's solve it step by step and explain the reasoning.

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🔍 Problem Summary:

We are given a scenario involving two Martians, A and B, who make statements about whether life exists on Mars.

- Both Martians are either truth-tellers (always tell the truth) or liars (always lie).
- We don't know which is which.
- The goal is to determine whether there is life on Mars based on their statements.

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🧩 Statements:

> Martian A says: "There is no life on Mars."
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> Martian B says: "At least one of us is lying."

We need to figure out:
1. Whether Martian A and B are truth-tellers or liars.
2. Whether there is life on Mars.

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✔ Step-by-step Analysis:

Let’s denote:
- Let L = "There is life on Mars."
- So, "No life on Mars" = ¬L
- Martian A says: ¬L
- Martian B says: "At least one of us is lying." → This means: A is lying OR B is lying → ¬(A tells truth) ∨ ¬(B tells truth)

Let’s consider possible cases.

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#### 🔹 Case 1: Assume Martian A is telling the truth

Then:
- A says "No life on Mars" → So ¬L is true → No life on Mars
- Since A is truthful, B must be either truthful or lying — we’ll check both.

Now, B says: "At least one of us is lying."

But if A is truthful, then for B’s statement to be true, at least one of them must be lying. But A is truthful, so B must be lying.

So:
- If B is lying, then B’s statement ("At least one of us is lying") is false.
- But if it's false, that means neither is lying → both are truthful.

Contradiction!

Because:
- B is lying → B's statement is false → "At least one of us is lying" is false → both are truthful.
- But we already assumed B is lying → contradiction.

So, B cannot be lying if A is truthful.

But if B is truthful, then B’s statement ("At least one of us is lying") must be true.

But A is truthful → so only B could be lying → but B is truthful → so no one is lying.

But then B’s statement ("at least one is lying") would be false, because nobody is lying.

Contradiction again.

Therefore, if A is truthful, we get a contradiction.

➡️ So A cannot be truthful → A is lying.

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#### 🔹 Case 2: Martian A is lying

Then:
- A says "No life on Mars" → this is false
- So the actual fact is: There IS life on Mars → L is true

Now, since A is lying, A is a liar.

Now consider B’s statement: "At least one of us is lying."

We already know A is lying → so at least one is lying → so the statement is true.

So B’s statement is true.

That means B is a truth-teller.

So:
- A: liar
- B: truth-teller
- Statement: "At least one is lying" → true (since A is lying)
- A said "No life on Mars" → false → so there is life on Mars

✔ All consistent.

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✔ Final Answer:

Yes, there is life on Mars.

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🧠 Explanation:

- If A were truthful, then there is no life on Mars.
- But that leads to a contradiction with B’s statement.
- Therefore, A must be lying → so "No life on Mars" is false → there is life on Mars.
- B says "At least one of us is lying" → since A is lying, this is true → B is truthful.
- No contradictions.

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🟩 Conclusion:

There is life on Mars.

And the Martians are:
- Martian A: Liar
- Martian B: Truth-teller

✔ Solved!