346 is related to 245 by certain logic. Following the same logic, 580 is related to 479. To which of the following is 613 related, following the same logic? (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 — A. Treat each number as a whole number, exactly as the note in the question insists.

Rule: second number = first number − 101.

346 − 101 = 245
580 − 101 = 479
613 − 101 = 512 → option (a)

Both worked pairs give the same gap, so the gap is the relation. Nothing else has to be true of the digits.

Why the others are wrong

• (b)
  460 — 613 − 460 = 153, not 101, so this breaks the constant gap that both given pairs share.
• (c)
  720 — 720 is larger than 613, but the relation takes something away — both given pairs move down, never up.
• (d)
  630 — 630 is also above 613, and only 17 above it. The rule subtracts a fixed 101.

A number analogy. Two worked pairs are given so that you can test a candidate rule twice before applying it to the third.

Start with the difference, because it is the cheapest test. 346 − 245 = 101 and 580 − 479 = 101, so a constant subtraction explains both pairs and no further rule is needed.

Only if the difference varies should you move on to ratios, squares, or digit reversal.

Key facts

• 346 − 245 = 101.
• 580 − 479 = 101.
• 613 − 101 = 512.
• The bracketed note bars breaking 613 into 6, 1 and 3 and operating on those digits.

Common traps

• Splitting the numbers into digits, which the note explicitly forbids.
• Fixing the rule from one worked pair and never testing it on the second.
• Picking an option larger than 613 when the relation clearly subtracts.

No directly related past PYQ was found.