Select the triad in which the numbers are related in the same way as are the numbers of the given triads. (25, 22, 47), (31, 24, 55) (NOTE : Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding /deleting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)

Correct — C. Settle the rule on the two given triads before looking at any option.

25 + 22 = 47
31 + 24 = 55

Rule: first number + second number = third number.

Test (18, 21, 39): 18 + 21 = 39, exactly the third number → option (c).

No other option adds up — 17 + 15 = 32, 22 + 19 = 41 and 27 + 25 = 52, against printed thirds of 22, 45 and 42.

Why the others are wrong

• (a)
  (17, 15, 22) — (17, 15, 22) gives 17 + 15 = 32, not 22. The difference 17 − 15 = 2 invites a subtraction reading that the given triads do not support.
• (b)
  (22, 19, 45) — (22, 19, 45) gives 22 + 19 = 41, four short of 45. On triad matching the arithmetic has to land exactly.
• (d)
  (27, 25, 42) — (27, 25, 42) gives 27 + 25 = 52, ten over 42. Subtracting instead reaches only 2, so no reading of this triple works.

Triad matching gives you two worked examples and asks for a third of the same kind. Both examples must satisfy whatever rule you propose — one is never enough.

Start with the simplest operations. Addition, subtraction, then product with a constant. Here plain addition fits both given triads, so there is no reason to look for anything more elaborate.

Key facts

• Both given triads satisfy first plus second equals third.
• 18 + 21 = 39 is the only option that meets that rule.
• The printed note bars digit-splitting, so 25 stays twenty-five throughout.

Common traps

• Building the rule from the first given triad alone.
• Choosing the nearest option rather than the exact one.
• Splitting numbers into digits, which the printed note forbids.

No directly related past PYQ was found.