Discussion
One entry is missing from the sequence set out below. Find the rule and name the term that completes the run.
7, 26, 63, 124, ?
Answer: B
Correct answer: 215
The gaps are 19, 37, 61, which follow no constant pattern, so the rule lies in the terms rather than in the steps between them. Each term is one less than the cube of its position: position 2 gives 7 and position 5 gives 124. The next position is 6, which gives 215. As a check, the same rule applied to the earlier positions reproduces 7, 26, 63, 124 exactly, so it accounts for every term shown and not merely the last. Adding the position number to a cube leaves the growth dominated by the cube, so the family is identified from the largest terms.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development