RAS question
In a certain code language, 'sky is blue' is coded as '5 3 7', 'blue is nice' is coded as '3 7 9', and 'nice sky far' is coded as '9 5 2'. What is the code for 'far'?
Correct answer: (C) 2.
In the given code language, the code for "far" is 2.
Explanation
This is a word-code matching question, solved by comparing repeated words across the coded statements. NCERT's Class X Mathematics text frames mathematics as reasoning through patterns, relationships, and clear logical argument; the same method applies here. In "sky is blue" = 5 3 7 and "blue is nice" = 3 7 9, the common words are "blue" and "is", so their codes must be the common numbers 3 and 7. That leaves "sky" matched with 5 in the first statement and "nice" matched with 9 in the second. Now use "nice sky far" = 9 5 2: since "nice" is 9 and "sky" is 5, the remaining code 2 must stand for "far".
Why the other options are wrong
- (A) 9 is already fixed as the code for "nice" from the comparison of "blue is nice" with the earlier common words.
- (B) 5 is the code for "sky", because it is the unmatched code left after removing the common codes from "sky is blue".
- (D) 3 is one of the common codes shared by "sky is blue" and "blue is nice", so it belongs to either "blue" or "is", not to "far".
Concept
This tests coding-decoding through common-term elimination, a recurring Reasoning and Mental Ability skill because it checks whether the candidate can isolate patterns instead of memorising a rule. Such questions reward clean comparison of overlapping information and a short logical chain.