Lesson 2 of 3 · Gaining / losing clock
Correct time
Clocks and Calendars · for IPMAT Indore, IPMAT Rohtak and JIPMAT · asked in JIPMAT 2025
The exam method
- Correct time. from x minutes slow to y minutes fast in T hours, the error changes by x + y; it is zero after x/(x + y) of the interval (JIPMAT 2024: 2 slow, 2.5 fast in 27 h → after 12 h).
Worked examples
Example 2EasyJIPMAT 2025
A watch is 1 minute slow at 1 p.m. Tuesday and 2 minutes fast at 1 p.m. Thursday. When was it right?
Solution: 5 a.m. Wednesday. 3 minutes in 48 hours; 1 minute takes 16 hours.
Watch out
- Per true hour vs per shown hour: "gains 5 seconds every minute" is per true minute.
Picked from the Gaining / losing clock note for this micro-concept automatically. The whole note: Gaining / losing clock.