Direction : A number arrangement machine when given an input line of numbers…
2021
Direction : A number arrangement machine when given an input line of numbers rearranges them following a particular rule in each step. The following is an illustration of input and rearrangement:
Input:84629 57426 76932 27483 49853 62434
Step I:273 84629 57426 76932 49853 62434
Step II: 53 273 84629 57426 76932 62434
Step III:572 53 273 84629 76932 62434
Step IV:23 572 53 273 84629 76932
Step V:732 23 572 53 273 84629
Step VI:2 732 23 572 53 273
Step VI is the last step of the given arrangement. Based on the given logic, rearrange the given input.
Input: 63825 49857 38679 72548 45328 95763
Which of the following number is second to the left of fifth number from left end in step IV?
- A.
37
- B.
72548
- C.
532
- D.
325
- E.
None of these
Attempted by 1 students.
Show answer & explanation
Correct answer: C
Concept
In a machine input–output problem you must first recover the fixed rule from the worked illustration, then replay that exact rule on the new input. Two independent rules govern this machine: (a) an ORDER rule that decides which number is pulled to the front in each step, and (b) a TRANSFORM rule that decides what value is written from the pulled number.
Recovering the rule from the illustration
Compare each illustration step with the value placed at the front:
Order rule: in every step the machine pulls the SMALLEST remaining five-digit number (the numbers are taken in ascending numeric order: 27483, 49853, 57426, 62434, 76932, 84629).
Transform rule: from the pulled number it keeps only the PRIME digits (2, 3, 5, 7), in their original left-to-right order, and discards the non-prime digits (0, 1, 4, 6, 8, 9). For example 27483 keeps 2, 7, 3 to give 273; 49853 keeps 5, 3 to give 53; 84629 keeps only 2.
The transformed value is placed at the LEFT end, and the pulled number is removed, so the list length stays at six each step.
Applying the rule to the new input
New Input: 63825 49857 38679 72548 45328 95763. Ascending order of the numbers is 38679, 45328, 49857, 63825, 72548, 95763, and their prime-digit values are 37, 532, 57, 325, 725, 573 respectively. Replaying the machine:
Step I — pull 38679 (smallest) → write 37: 37 | 63825 49857 72548 45328 95763
Step II — pull 45328 → write 532: 532 | 37 63825 49857 72548 95763
Step III — pull 49857 → write 57: 57 | 532 37 63825 72548 95763
Step IV — pull 63825 → write 325: 325 | 57 532 37 72548 95763
Reading the required position
Step IV is: 325, 57, 532, 37, 72548, 95763. The fifth number from the left end is 72548. ‘Second to the left’ of it means two positions further left, i.e. the third element from the left, which is 532.
Cross-check
Counting back from 72548: one position left is 37, two positions left is 532. So the required number is 532, which matches the prime-digit value written from 45328. The reference number 72548 is the fifth element itself (not to its left), and 325 sits at the extreme left of Step IV, four places away from the fifth number — neither is two-to-the-left of the fifth number.