Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number result(s) in the second number. Similarly, certain mathematical operation(s) on the second number result(s) in the third number and so on. Which of the given options follows the same set of operations as in the given sets? (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.) 17 – 19 – 16 – 20; 22 – 24 – 21 – 25

Correct — B. Read the operations off the first set, confirm on the second, then test the options.

17 → 19 is +2
19 → 16 is −3
16 → 20 is +4

Confirm on the second set: 22 + 2 = 24, 24 − 3 = 21, 21 + 4 = 25. The chain holds.

Now apply +2, −3, +4 to option (b):
15 + 2 = 17
17 − 3 = 14
14 + 4 = 18

All three steps land on the printed numbers, so 15 – 17 – 14 – 18 is the match — option (b).

Why the others are wrong

• (a)
  11 – 13 – 10 – 15 — 11 + 2 = 13 and 13 − 3 = 10 both work, but the last step needs 10 + 4 = 14, and the option prints 15.
• (c)
  18 – 20 – 16 – 14 — 18 + 2 = 20 is right, and then the rule demands 20 − 3 = 17. The option prints 16, so it fails at the second step.
• (d)
  16 – 18 – 12 – 16 — 16 + 2 = 18 is right, and then the rule demands 18 − 3 = 15. The option prints 12, which is a subtraction of 6.

Two worked sets are given so that the chain of operations can be pinned down rather than guessed.

Derive the operations from the first set, then verify them against the second before touching the options — a rule that fits only one set is not a rule.

The stem's note is binding: operate on the whole number. Splitting 17 into 1 and 7 is explicitly disallowed, which rules out the digit tricks that would otherwise fit some options.

Then test each option step by step and stop at the first failure. Every wrong option here clears the first step, so the discrimination happens at step two or step three.

Key facts

• The chain here is +2, then −3, then +4.
• The stem forbids breaking a number into its digits, so all operations act on the whole number.
• Both given sets must satisfy the rule before it is applied to the options.
• Every wrong option clears the first step, so testing must continue to steps two and three.

Common traps

• Testing the first step only and picking the first option that survives it.
• Splitting a two-digit number into its digits, which the note in the stem forbids.

No directly related past PYQ was found.