In a certain code language, ‘SET’ is coded as ‘37’ and ‘MIX’ is coded as ‘35’. How will ‘WAR’ be coded in that language?

Correct — B. Rule: replace each letter by its position counted from the end of the alphabet, that is 27 minus its normal position, then add the three values.

Check both given codes.
SET: S = 8, E = 22, T = 7, and 8 + 22 + 7 = 37.
MIX: M = 14, I = 18, X = 3, and 14 + 18 + 3 = 35.

Now WAR.
W = 27 - 23 = 4
A = 27 - 1 = 26
R = 27 - 18 = 9

4 + 26 + 9 = 39, option (b).

Why the others are wrong

• (a)
  29 — A alone scores 26 and W adds 4, which is 30 before R has been counted at all. 29 sits below that, so the rule cannot reach it.
• (c)
  21 — 21 is smaller than 26, the value A carries on its own. Any word containing an A codes to at least 26.
• (d)
  32 — 32 would need R to be worth 2. R is the ninth letter from the end of the alphabet, so it is worth 9 and the total is 39.

This is a positional code, and the only real decision is which direction to count. Forward positions give SET = 19 + 5 + 20 = 44, which does not match 37, so try the reverse.

Counting from the end, a letter is worth 27 minus its forward position, so A is 26 and Z is 1. That gives 37 for SET and 35 for MIX, and two matches out of two is enough to commit.

There is a shortcut for three-letter words: the reverse total equals 81 minus the forward total, because 3 x 27 = 81.

Key facts

• Reverse position equals 27 minus forward position, so A is 26 and Z is 1.
• SET codes to 8 + 22 + 7 = 37 and MIX codes to 14 + 18 + 3 = 35.
• For any three-letter word the reverse total equals 81 minus the forward total.

Common traps

• Using 26 minus the position rather than 27 minus the position, which gives 36 for WAR.
• Adding the forward positions and then forgetting to subtract the total from 81.

No directly related past PYQ was found.