Announcements
UPSC Foundation 2026 Prime Batch - Admissions Open JPSC 14th CCE Complete Course 2025 - Enroll Now Mains Practice Questions Programme - Limited Seats Daily Current Affairs - Free Access UPSC Prelims Test Series 2026 - 5000+ MCQs
+91 91025 57680
learnpro Civil Services Get app
LearnPro Menu
Home Current Affairs Download Notes All Articles
UPSC
UPSC NOTES
STATE PSC
OPTIONAL SUBJECTS
CURRENT AFFAIRS
DAILY EDITORIAL
COURSES
UPSC PYQ Solutions Mains Practice Questions WhatsApp Counselling Call +91 91025 57680 Online Courses

PYQ Question

What is the number of selections of 10 consecutive things out of 12 things in a circle taken in the clockwise direction?

What is the number of selections of 10 consecutive things out of 12 things in a circle taken in the clockwise direction?
  1. A. 3
  2. B. 11
  3. C. 12
  4. D. 66

Answer: C

Explanation

Consider the 12 things arranged in a circle, labeled 1 to 12 in a clockwise direction. We need to select 10 consecutive things. This means we are essentially choosing a starting point for our sequence of 10. If we start at thing 1, the selection is (1, 2, 3, 4, 5, 6, 7, 8, 9, 10). If we start at thing 2, the selection is (2, 3, 4, 5, 6, 7, 8, 9, 10, 11). This continues until we start at thing 12, which gives the selection (12, 1, 2, 3, 4, 5, 6, 7, 8, 9). Each of the 12 things can serve as the unique starting point for a sequence of 10 consecutive things. Therefore, there are 12 such selections.