Instruction: In a language, if ‘red green blue’ is coded as ‘ka ta na’, ‘blue white black’ as ‘na ja sa’, and ‘white red’ as ‘ja ka’, Question: what is the code for ‘green’?

Correct — A.
Rule: a word in two statements takes the code those two share.

blue is in statements 1 and 2 → shared code na.
white is in statements 2 and 3 → shared code ja.
red is in statements 1 and 3 → shared code ka.

Statement 1 is 'red green blue' = 'ka ta na'. With red = ka and blue = na, green = ta → option (a).

Why the others are wrong

• (b)
  na — na is the code statements 1 and 2 share, and blue is the word they share. So na is blue, not green.
• (c)
  ka — ka is the code statements 1 and 3 share, and their shared word is red. So ka is red, not green.
• (d)
  ja — ja is not in statement 1 at all, and green appears nowhere else. ja is shared by statements 2 and 3, so it codes white.

In a word-code question, you cannot assume a code sits in the same place as its word. What you can rely on is overlap: a word shared by two statements must take the code those two statements share.

Match each shared word to its shared code. The word left over in a statement then takes the code left over. green appears in just one statement, so it is found last, by elimination.

Key facts

• blue = na, white = ja and red = ka, each from a pair of statements.
• green = ta, the code left over in 'red green blue' = 'ka ta na'.
• black = sa, the code left over in 'blue white black' = 'na ja sa'.

Common traps

• Matching codes by position, which fails once a statement's order is scrambled
• Taking a shared code such as na or ka for green, when it belongs to the word the two statements share

No directly related past PYQ was found.