Question

By 7 p.m., Joe had typed 4 pages of his paper. At 8:30 p.m., he had completed 10 pages. Calculate his typing rate in minutes per page?

Answer 1

Hint: To solve this question where we have to find the typing rate in minutes per page, first convert the given time in hours to minutes. Then calculate the difference between the time intervals and simply find the ratio of the time interval to the pages typed during that is the specific time interval to get the typing rate.

Complete step-by-step answer:
Given:
The initial time when Joe typed 4 pages: 7 p.m.
The final time when Joe had completed 10 pages: 8:30 p.m.
The time interval, that is, the total number of hours between the initial and the final time will be 1 hour and 30 minutes.
Since, we know that 1 hour consists of 30 minutes so converting the total number of hours between the initial and final time will be,
$\Rightarrow 1hr30\min =60\min +30\min =90\min$
At the starting time, the total number of pages typed were $4\;$ and by the final time, the number of completed pages reached a total of $10\;$ pages.
So, the number of pages typed in between the initial and final time will be $10-4=6$
Now, we can calculate the rate of typing by simply dividing the time interval to the number of pages written in that specific time interval, that is,
$\Rightarrow ROT=\dfrac{90}{6}=15$ , where ROT means the rate of typing.
Therefore, the typing rate of Joe in minutes per page will be $15\;$ minutes per page.

Note: The above question can also be solved by the unitary method which involves finding the value of a single unit first and then multiplying the single unit value to find the necessary value. The unitary method has two variations that include direct variation and inverse variation.