Discussion
Ananth takes 6 hours and Bharath takes 4 hours to read a book. Both started reading copies of the book at the same time. After how many hours is the number of pages to be read by Ananth, twice that to be read by Bharath? Assume Ananth and Bharath read all the pages with constant pace.
Answer: C
After 3 hours.
Take the book as 1 unit. Ananth reads \(1/6\) per hour and Bharath \(1/4\) per hour, so after \(t\) hours the parts still to be read are \(1 - t/6\) and \(1 - t/4\).
\[ \begin{aligned} 1 - \frac{t}{6} &= 2\left(1 - \frac{t}{4}\right) \\ \frac{t}{2} - \frac{t}{6} &= 1 \\ \frac{t}{3} = 1 &\Rightarrow t = 3 \end{aligned} \]
Check: after 3 hours Ananth has half the book left and Bharath a quarter, and a half is twice a quarter. After 1 or 2 hours Ananth's remainder is less than twice Bharath's (5/6 against 3/2, 2/3 against 1); at 4 hours Bharath has finished while Ananth still has a third to read.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development