RAS question
Statement: 'All mangoes are fruits. Some fruits are sweet.' Conclusion I: Some mangoes are sweet. Conclusion II: All fruits are mangoes. Which conclusion(s) follow(s)?
Correct answer: (D) Neither I nor II follows.
Neither conclusion follows because the premises prove only that all mangoes are fruits and some fruits are sweet, not that mangoes overlap with sweet fruits or that all fruits are mangoes.
Explanation
A common mistake in this type of syllogism is treating a possible conclusion as certain. Under the SATHEE syllogism rules, a conclusion must be 100 per cent certain. A universal statement cannot simply be reversed, and pairing an "all" statement with a "some" statement gives no definite conclusion here. "All mangoes are fruits" establishes only that every mango belongs to the class of fruits. "Some fruits are sweet" establishes that some members of the fruit class are sweet, but not that any mango is among them. Conclusion I is therefore not certain. Conclusion II wrongly reverses the first statement: all mangoes being fruits does not make all fruits mangoes.
Why the other options are wrong
- (A) Conclusion I wrongly assumes that the sweet fruits mentioned in the second statement must include mangoes, which the premises never guarantee.
- (B) Conclusion II reverses the universal statement; "all mangoes are fruits" does not imply that every fruit is a mango.
- (C) Neither conclusion follows: Conclusion I requires an unproven overlap between mangoes and sweet fruits, while Conclusion II invalidly reverses the mango-fruit relationship.
Concept
This tests whether conclusions follow with certainty from statements using quantifiers such as "all" and "some". Such questions recur in RAS reasoning because candidates must distinguish logically guaranteed conclusions from assumptions that merely seem plausible.