Kajol reads 1/3 part of a book in 01 hour. She reads this book 2(1/5) hours.…
2013
Kajol reads 1/3 part of a book in 01 hour. She reads this book 2(1/5) hours. How much part of this book will remain to read?
- A.
1/3
- B.
1/5
- C.
4/15
- D.
7/15
Attempted by 1 students.
Show answer & explanation
Correct answer: C
Concept: When work happens at a constant rate, the fraction of the task completed after time t equals (rate per unit time) multiplied by t, and the fraction remaining equals 1 minus the fraction completed.
Application:
Kajol's reading rate is 1/3 of the book per hour.
Convert the reading time to an improper fraction: 2(1/5) hours = 11/5 hours.
Part of the book read = rate x time = 1/3 x 11/5 = 11/15.
Part remaining = 1 - 11/15 = 15/15 - 11/15 = 4/15.
Cross-check: At a rate of 1/3 of the book per hour, the whole book takes 3 hours to finish. Time still needed after 11/5 hours = 3 - 11/5 = 4/5 hours, and (4/5) divided by 3 = 4/15 of the book -- the same fraction, confirming the result.