Difficulty: Medium
Correct Answer: False
Explanation:
Introduction / Context:
This question presents a common reasoning error where a conclusion is drawn based solely on a shared property, in this case colour. The statement says that the presence of calcium in milk makes it white. Since rice is also white, the conclusion claims that rice must also contain calcium. The task is to evaluate whether this conclusion is logically valid and how it should be classified: true, probably true, false or something that cannot be determined from the given information.
Given Data / Assumptions:
Concept / Approach:
The reasoning in the conclusion confuses a specific cause-effect relationship in one context with a general rule. Even if we accept that calcium causes milk to be white, it does not follow that everything white must contain calcium. Different substances can share the same observable property (colour) for entirely different structural or chemical reasons. The argument is an example of the fallacy of affirming the consequent: from "If calcium is present in milk, then milk is white" and "rice is white" it incorrectly concludes that rice has calcium.
Step-by-Step Solution:
Step 1: Translate the statement about milk into a conditional form: If milk contains calcium, then milk is white.
Step 2: Note that this does not say that only calcium can make a substance white. There could be many other reasons a substance appears white.
Step 3: Observe that rice is white, but we have no statement connecting rice, whiteness and calcium.
Step 4: The conclusion assumes that because milk's whiteness is due to calcium, rice's whiteness must also be due to calcium.
Step 5: This is a logically invalid pattern of reasoning. From "A causes B in one case" and "C also shows B", we cannot infer that "C also has A".
Step 6: In fact, basic science tells us that rice appears white mainly due to its starch content and structure, not primarily because of calcium.
Step 7: Therefore, the argument that rice also contains calcium based on whiteness alone is false as a conclusion.
Verification / Alternative check:
To see the flaw clearly, consider another example: "The presence of sugar in cakes makes them sweet. Mangoes are also sweet. Therefore, mangoes must contain sugar from cakes." This is obviously wrong, because sweetness in mangoes arises from natural fruit sugars and other compounds, not from cake ingredients. Similarly, whiteness in different substances can arise from different materials and structures. The conclusion about rice having calcium based solely on colour is equally flawed. Therefore, both logically and based on basic scientific knowledge, the conclusion is best classified as false.
Why Other Options Are Wrong:
It cannot be classified as True, because the reasoning pattern is invalid and the conclusion does not logically follow from the premises.
Probably true is not appropriate, because there is no strong probabilistic support; whiteness alone does not make calcium content likely.
Cannot say is weaker than necessary here, because the argument form is clearly incorrect, and the shared property does not support the conclusion.
Common Pitfalls:
One common mistake is to assume that sharing a visible property, such as colour, proves a shared internal composition. Another pitfall is to read the initial statement as saying that calcium is the only cause of whiteness in any substance, which it does not claim. Reasoning questions often use this structure to test whether the candidate can distinguish between a specific explanation and an overgeneralised rule. To avoid such errors, always check whether the conclusion simply restates a property of the original subject or improperly extends it to other cases without evidence.
Final Answer:
The conclusion that rice also contains calcium, based solely on its whiteness, is false.
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