Answer:
48 pages per hour; 3 hours per page
Explanation:
A). You can find the unit rate for pages per hour by first multiplying the hours by its reciprocal, 4, which essentially becomes 1 hour and what you do to one side must be done to the other side, so multiplying 12 by 4 gets you 48 pages. Therefore, Leo reads 48 pages per hour.
B). To find hours per page, you do the same thing, except that this time, you divide 12 on each side because you are trying to find the hours per page. 12 pages divided by 12 gets you 1 page and dividing 1/4 by 12 is the same thing as multiplying 1/4 by 12 since when dividing fractions with another fraction, the method is to use the reciprocal of the second fraction (in this case, 1/12 becomes 12) and you change the sign to its inverse and you simplify. A helpful acronym you can use is this. KEEP IT, CHANGE IT, FLIP IT . You keep the first fraction as it is, change the sign to its inverse, and flip the second fraction (virtually, the reciprocal). Therefore, in this case, it becomes 1/4 times 12 and 12 divided by 4 is nothing but 3.
Thus, Leo takes 3 hours to read each page.
Hope this helped! :D