Q. A clock loses 5 minutes every hour. It is set correctly at 8:00 a.m. What time will it show at 8:00 p.m.? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ģ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§Ž:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āϏāĻ āĻŋāĻāĻāĻžā§ąā§ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ āϤā§āύā§āϤ⧠āϏāύā§āϧāĻŋāϝāĻŧāĻž ā§Ž:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
Soln
The clock loses 5 minutes every hour. (āĻāĻĄāĻŧā§āĻā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ģ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤)
This means that after every real hour, the clock shows 5 minutes less than the actual time. (āĻ
ā§°ā§āĻĨāĻžā§, āĻĒā§ā§°āĻā§āϤ ā§§ āĻāĻŖā§āĻāĻž āĻĒāĻžā§° āĻš'āϞ⧠āĻāĻĄāĻŧā§āĻā§ā§ąā§ ā§Ģ āĻŽāĻŋāύāĻŋāĻ āĻāĻŽ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāϝāĻŧāĨ¤)
- Actual time passed(āĻŽā§āĻ āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ) = 12 hours (āĻĒā§ā§°āĻā§āϤ āϏāĻŽāϝāĻŧ āĻĒāĻžā§° āĻšā§āĻā§ = ⧧⧍ āĻāĻŖā§āĻāĻž)
- Clock loses = 5 minutes per hour (āĻāĻĄāĻŧā§ āĻĒāĻŋāĻ āĻĒā§°ā§ = āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ģ āĻŽāĻŋāύāĻŋāĻ)
Total Loss = 12 × 5 = 60 minutes = 1 hourAns / āĻāϤā§āϤ⧰: Actual Time = 8:00 p.m., Clock is 1 hour slow
Therefore, 8:00 − 1:00 = 7:00, The clock will show 7:00 p.m.

Shortcut / āϏāĻšāĻ āύāĻŋāϝāĻŧāĻŽ: Total Time Lost = (Number of Hours) × (Loss per Hour)
[āĻŽā§āĻ āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ = (āĻŽā§āĻ āĻāĻŖā§āĻāĻž) × (āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžā§° āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ)]
Then: Clock Time = Actual Time − Total Time Lost (āĻāĻĄāĻŧā§ā§° āϏāĻŽāϝāĻŧ = āĻĒā§ā§°āĻā§āϤ āϏāĻŽāϝāĻŧ − āĻŽā§āĻ āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ)
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Practice Set (āĻ
āĻā§āϝāĻžāϏ⧰ āĻĒā§ā§°āĻļā§āύ) – Slow Clock
Find the time shown by the slow clock. (āϧā§ā§° āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ āĻāϞāĻŋāĻā§ąāĻžāĨ¤)
1. A clock loses 2 minutes every hour. It is set correctly at 6:00 a.m. What time will it show at 12:00 noon? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ⧍ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§Ŧ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āϏāĻ āĻŋāĻāĻā§ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ ⧧⧍:ā§Ļā§Ļ āĻĻā§āĻĒā§°ā§āϝāĻŧāĻž āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
2. A clock loses 3 minutes every hour. It is set correctly at 7:00 a.m. What time will it show at 3:00 p.m.? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Š āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ ā§Š:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
3. A clock loses 4 minutes every hour. It is set correctly at 8:00 a.m. What time will it show at 6:00 p.m.? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ē āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§Ž:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ āϏāύā§āϧāĻŋāϝāĻŧāĻž ā§Ŧ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
4. A clock loses 5 minutes every hour. It is set correctly at 9:00 a.m. What time will it show at 9:00 p.m.? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ģ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ⧝:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ ā§°āĻžāϤāĻŋ ⧝:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
5. A clock loses 6 minutes every hour. It is set correctly at 10:00 a.m. What time will it show at 4:00 p.m. ? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ŧ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§§ā§Ļ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ ā§Ē:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
6. A clock loses 5 minutes every hour. It is set correctly at 12:00 noon. What time will it show at 6:00 p.m.? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ģ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ ⧧⧍:ā§Ļā§Ļ āĻĻā§āĻĒā§°ā§āϝāĻŧāĻž āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ āϏāύā§āϧāĻŋāϝāĻŧāĻž ā§Ŧ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
7. A clock loses 10 minutes every hour. It is set correctly at 5:00 a.m. What time will it show at 11:00 a.m. ? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§§ā§Ļ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§Ģ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ ā§§ā§§:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
8. A clock loses 8 minutes every hour. It is set correctly at 2:00 p.m. What time will it show at 8:00 p.m. ? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§Ž āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ ⧍:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ ā§Ž:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
9. A clock loses 1 minute every hour. It is set correctly at 8:00 a.m. What time will it show at 8:00 p.m. ? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§§ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§Ž:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ āϏāύā§āϧāĻŋāϝāĻŧāĻž ā§Ž:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
10. A clock loses 7 minutes every hour. It is set correctly at 6:00 a.m. What time will it show at 6:00 p.m.? (āĻāĻāύ āĻāĻĄāĻŧā§ āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ ā§ āĻŽāĻŋāύāĻŋāĻ āĻĒāĻŋāĻ āĻĒā§°ā§āĨ¤ āĻĒā§ā§ąāĻž ā§Ŧ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻā§āĻ āĻā§°āĻž āĻšā§āĻāĻŋāϞāĨ¤ āϏāύā§āϧāĻŋāϝāĻŧāĻž ā§Ŧ:ā§Ļā§Ļ āĻŦāĻāĻžāϤ āĻāĻĄāĻŧā§āĻā§ā§ąā§ āĻāĻŋāĻŽāĻžāύ āϏāĻŽāϝāĻŧ āĻĻā§āĻā§ā§ąāĻžāĻŦ ?)
Shortcut / āϏāĻšāĻ āύāĻŋāϝāĻŧāĻŽ
- Total Time Lost = Hours Passed × Loss per Hour (āĻŽā§āĻ āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ = āĻĒāĻžā§° āĻšā§ā§ąāĻž āĻāĻŖā§āĻāĻž × āĻĒā§ā§°āϤāĻŋ āĻāĻŖā§āĻāĻžāϤ āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ)
- Clock Time = Actual Time − Total Time Lost (āĻāĻĄāĻŧā§ā§° āϏāĻŽāϝāĻŧ = āĻĒā§ā§°āĻā§āϤ āϏāĻŽāϝāĻŧ − āĻŽā§āĻ āĻĒāĻŋāĻ āĻĒā§°āĻž āϏāĻŽāϝāĻŧ)