Select the set in which the numbers are related in the same way as are the numbers of the following sets. (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.) (25, 300, 6) (19, 342, 9)
- (a)(24, 600, 5)
- (b)(14, 364, 7)
- (c)(17, 476, 7)
- (d)(18, 288, 8)
Answer
Why
Correct — D. Find one relation that ties all three numbers of both sample sets, not just two of them.
(25, 300, 6): 25 × 6 = 150, and 150 × 2 = 300
(19, 342, 9): 19 × 9 = 171, and 171 × 2 = 342
Rule: middle = first × third × 2.
Test the options on their outer numbers:
24 × 5 × 2 = 240
14 × 7 × 2 = 196
17 × 7 × 2 = 238
18 × 8 × 2 = 288 → option (d)
Why the others are wrong
- (a)(24, 600, 5) — 24 × 5 × 2 = 240, not 600. The printed 600 is 24 × 5 × 5, so this set uses a multiplier of 5 where the samples use 2.
- (b)(14, 364, 7) — 14 × 7 × 2 = 196. The printed 364 is not even a whole-number multiple of 14 × 7 = 98, so no constant multiplier reaches it.
- (c)(17, 476, 7) — 17 × 7 × 2 = 238, and the printed 476 is that doubled again. The set works on a multiplier of 4, twice what the samples fix.
Concept
A three-number set analogy asks for a relation that uses every number in the set. Any rule that ignores one of the three will let several options through.
Start by multiplying the outer pair and comparing the product with the middle number. If the ratio is the same in both sample sets, that ratio is the rule.
25 × 6 = 150 against a middle of 300, and 19 × 9 = 171 against 342, both give a ratio of 2.
Two of the wrong options are near misses on the same structure: option (a) multiplies by 5 and option (c) by 4. Anyone who checks only that the middle number is divisible by the outer two will find three options acceptable.
Key facts
- In both sample sets the middle number is the product of the outer two, doubled.
- 25 × 6 = 150 and 19 × 9 = 171, against middles of 300 and 342.
- For the answer, 18 × 8 = 144 and 144 × 2 = 288.
Study next
Common traps
- Checking only that the middle number divides by the outer two, which options (a) and (c) also pass.
- Multiplying the outer pair and stopping there, which gives 144 for the answer and makes it look wrong.
- Splitting 300 into 3, 0 and 0, which the note in the stem forbids.
The same whole-number note heads a pair analogy at Q.2, a related-number item at Q.5 and an odd-one-out at Q.7 in this shift's Reasoning section (10 Sep 2024, 12:30).
Related PYQs
No directly related past PYQ was found.