RAS question
In a certain code language, 'sky is blue' is written as '5 3 9', 'blue is bright' is written as '9 3 7'. What is the code for 'sky'?
Correct answer: (B) 5.
In the given code language, the code for sky is 5.
Explanation
Compare the two coded statements instead of trying to assign numbers by guesswork. The words common to both statements are is and blue, and the codes common to both code groups are 3 and 9. Here, is = 3 and blue = 9. In the first statement, sky is blue is coded as 5 3 9; after removing the codes already used for is and blue, the only code left is 5. NCERT's National Curriculum Framework for Foundational Stage treats logic puzzles and problem-solving activities as ways to build logical deduction, which is exactly the reasoning used here: isolate what repeats, then identify the unmatched term.
Why the other options are wrong
- (A) 3 is already matched with the common word is, so it cannot also be the code for sky in this one-to-one coding pattern.
- (C) 9 is already matched with blue, the other word common to both statements.
- (D) 7 appears only in the second coded statement, where the new word is bright, not sky.
Concept
This tests coding-decoding through common-term comparison: repeated words reveal repeated codes, and the remaining unmatched code gives the target word. RAS reasoning questions often use this pattern because it checks disciplined elimination rather than calculation.