A class starts at 11:00 am and lasts till 2:27 pm. Four periods of equal duration are held during this interval. After every period, a rest of 5 minutes is given to the students. The exact duration of each period is:
Answer & explanation
Answer: (a) 48 minutes
The class lasts 207 minutes. Four periods have three 5-minute rests between them, since the last period ends the class, so each period is (207 − 15) ÷ 4 = 48 minutes.
- 11:00 am to 2:27 pm = 3 h 27 min = 207 minutes.
- Four periods have three rests between them: 3 × 5 = 15 minutes.
- Teaching time = 207 − 15 = 192 minutes; each period = 192 ÷ 4 = 48 minutes.
- Check: 48 + 5 + 48 + 5 + 48 + 5 + 48 = 207.
Remember · n periods in a block have n − 1 breaks between them: subtract the breaks, then divide by n.
Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·