To find out how many papers Mr. Harris will grade in 60 minutes, we can first calculate the rate at which he grades papers:
- In 5 minutes, he grades 2 papers
- In 15 minutes, he grades 6 papers
- In 35 minutes, he grades 14 papers
- In 50 minutes, he grades 20 papers
First, we can calculate the rate at which he grades papers (papers per minute) by finding the difference in papers graded over the difference in time:
- From 5 to 15 minutes: (6 papers - 2 papers) / (15 minutes - 5 minutes) = 4 papers / 10 minutes = 0.4 papers per minute
- From 15 to 35 minutes: (14 papers - 6 papers) / (35 minutes - 15 minutes) = 8 papers / 20 minutes = 0.4 papers per minute
- From 35 to 50 minutes: (20 papers - 14 papers) / (50 minutes - 35 minutes) = 6 papers / 15 minutes = 0.4 papers per minute
Since the rate at which he grades papers is consistent at 0.4 papers per minute, Mr. Harris will grade 0.4 * 60 = 24 papers in 60 minutes.
Therefore, Mr. Harris will grade 24 papers in 60 minutes. So the answer is 24 papers.
Mr. Harris graded papers at the end of the school day. The table below shows how many papers he graded in minutes.
Minutes Number of papers graded
5 2
15 6
35 14
50 20
At this rate, how many papers will Mr. Harris grade in 60 minutes?
21 papers
23 papers
24 papers
34 papers
1 answer