If Arif reads 39 pages in half an hour, how long will she take to finish a 1287-page book?
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Answer: B. 16.5 Hours
Explanation
Reading thirty-nine pages in half an hour establishes a reading speed of seventy-eight pages per hour. To find the total duration required, divide the complete book length of twelve eighty-seven pages by the hourly reading rate. Dividing twelve eighty-seven by seventy-eight results in a total completion time of sixteen point five hours. Reading speed represents a standard rate calculated by dividing total pages read by elapsed time in hours. Unit rate calculations allow students to scale work performance metrics across larger quantities and durations. Decimal time representations convert fractional hour remainders into standard thirty-minute increments for clarity.
Option A suggests sixteen hours, underestimating the time required to read the remaining fraction of pages. Option C proposes seventeen hours, overestimating the total duration needed by failing to calculate the exact decimal quotient. Option D offers fifteen point five hours, which falls short of the true mathematical division result.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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