We can write the following equation:
where y is the number of pages Robert writes, x is the number of hours and k represents the rate.
Since Robert can write 1/3 page in 1/4 hour, we have:
substituting these values on the equation we get
to solve for k, we can multiply both sides of the equation by 4 to get the following:
therefore, Robert writes 1 1/3 pages per hour