Type 7: Fast Clock / āĻĻā§ā§°ā§āϤ āϘāĻĄāĻŧā§€ (Fast Clock)






Q. A clock gains 2 minutes every hour. After 10 hours, it shows 12:00. What was the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ⧍ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§§ā§Ļ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ āϘāĻĄāĻŧā§€āĻŸā§‹ā§ąā§‡ ⧧⧍:ā§Ļā§Ļ āĻĻ⧇āĻ–ā§ā§ąāĻžāχāĨ¤ āϤ⧇āĻ¨ā§āϤ⧇ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ āφāĻ›āĻŋāϞ ?)


Soln

The clock gains 2 minutes every hour. This means that after every real hour, the clock shows 2 minutes more than the actual time. (āϘāĻĄāĻŧā§€āĻŸā§‹ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ⧍ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ āĻ…ā§°ā§āĻĨāĻžā§Ž, āĻĒā§ā§°āĻ•ā§ƒāϤ ā§§ āϘāĻŖā§āϟāĻž āĻĒāĻžā§° āĻš'āϞ⧇ āϘāĻĄāĻŧā§€āĻŸā§‹ā§ąā§‡ ⧍ āĻŽāĻŋāύāĻŋāϟ āĻŦ⧇āĻ›āĻŋ āϏāĻŽāϝāĻŧ āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤)


Time passed = 10 hours, Clock gains = 2 minutes per hour

Total Gain = 10×2=20 minutes (āĻĒāĻžā§° āĻšā§‹ā§ąāĻž āϏāĻŽāϝāĻŧ = ā§§ā§Ļ āϘāĻŖā§āϟāĻž, āϘāĻĄāĻŧā§€ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇ = āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ⧍ āĻŽāĻŋāύāĻŋāϟāĻŽā§āĻ  āφāĻ—āĻŦāĻĸāĻŧāĻž āϏāĻŽāϝāĻŧ = 10×2 = 20 āĻŽāĻŋāύāĻŋāϟ

Clock Time = 12:00, Correct Time = Clock Time − Total Gain


 = 12:00 − 20 minutes =11:40


āϘāĻĄāĻŧ⧀⧰ āϏāĻŽāϝāĻŧ = ā§§ā§¨:ā§Ļā§Ļ, āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ = āϘāĻĄāĻŧ⧀⧰ āϏāĻŽāϝāĻŧ − āĻŽā§āĻ  āφāĻ—āĻŦāĻĸāĻŧāĻž āϏāĻŽāϝāĻŧ

12:00 − 20 āĻŽāĻŋāύāĻŋāϟ = 11:40

 

Ans / āωāĻ¤ā§āϤ⧰: The correct time was 11:40





  • Total Gain = Hours Passed × Gain per Hour (āĻŽā§āĻ  āφāĻ—āĻŦāĻĸāĻŧāĻž āϏāĻŽāϝāĻŧ = āĻĒāĻžā§° āĻšā§‹ā§ąāĻž āϘāĻŖā§āϟāĻž × āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ āφāĻ—āĻŦāĻĸāĻŧāĻž āϏāĻŽāϝāĻŧ)

  • Correct Time = Clock Time − Total Gain (āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ = āϘāĻĄāĻŧ⧀⧰ āϏāĻŽāϝāĻŧ − āĻŽā§āĻ  āφāĻ—āĻŦāĻĸāĻŧāĻž āϏāĻŽāϝāĻŧ)


===========================================


Practice Set Fast Clock : Shortcut / āϏāĻšāϜ āύāĻŋāϝāĻŧāĻŽ


 :  āĻ…āĻ­ā§āϝāĻžāϏ⧰ āĻĒā§ā§°āĻļā§āύ – āĻĻā§ā§°ā§āϤ āϘāĻĄāĻŧā§€

  1. A clock gains 1 minute every hour. After 8 hours, it shows 4:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ā§§ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§Ž āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ā§Ē:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  2. A clock gains 2 minutes every hour. After 6 hours, it shows 3:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ⧍ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§Ŧ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ā§Š:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  3. A clock gains 3 minutes every hour. After 10 hours, it shows 8:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ā§Š āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§§ā§Ļ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ā§Ž:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  4. A clock gains 4 minutes every hour. After 5 hours, it shows 12:00 noon. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ā§Ē āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§Ģ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ⧧⧍:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  5. A clock gains 5 minutes every hour. After 12 hours, it shows 9:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ā§Ģ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ⧧⧍ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ⧝:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  6. A clock gains 6 minutes every hour. After 8 hours, it shows 7:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ā§Ŧ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§Ž āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ā§­:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  7. A clock gains 10 minutes every hour. After 6 hours, it shows 5:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ā§§ā§Ļ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ā§Ŧ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ā§Ģ:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)

  8. A clock gains 2 minutes every hour. After 12 hours, it shows 6:00 p.m. What is the correct time ? (āĻāĻ–āύ āϘāĻĄāĻŧā§€ āĻĒā§ā§°āϤāĻŋ āϘāĻŖā§āϟāĻžāϤ ⧍ āĻŽāĻŋāύāĻŋāϟ āφāĻ—āĻŦāĻžāĻĸāĻŧ⧇āĨ¤ ⧧⧍ āϘāĻŖā§āϟāĻžā§° āĻĒāĻŋāĻ›āϤ ā§Ŧ:ā§Ļā§Ļ āĻŦāϜāĻž āĻĻ⧇āĻ–ā§ā§ąāĻžāϝāĻŧāĨ¤ āϏāĻ āĻŋāĻ• āϏāĻŽāϝāĻŧ āĻ•āĻŋāĻŽāĻžāύ ?)