To find out how long it will take Iris to complete the entire floor, we can use the information that she completes 23 of the floor in 13 of an hour.
To calculate the rate at which she completes the floor, we can divide the floor completed (23) by the time taken (13):
Floor completed / Time taken = Rate
23 / 13 = 1.7692
So, Iris completes the floor at a rate of approximately 1.7692 units per hour.
To find out how long it will take her to complete the entire floor, we can set up a proportion:
Partial floor completed / Time taken = Entire floor / Unknown time
Using the rate we found (1.7692 units per hour), we know that 23 units of the floor were completed in 13 of an hour. So, we can set up the proportion:
23 / 13 = Entire floor / Unknown time
Now, we can solve for the unknown time. Cross-multiplying, we get:
23 * Unknown time = 13 * Entire floor
Unknown time = (13 * Entire floor) / 23
Given that 1 unit of the floor takes 1 hour to complete, we can substitute Entire floor with 1:
Unknown time = (13 * 1) / 23
Unknown time = 13 / 23
Therefore, Iris will take approximately 0.5652 hours to complete the entire floor.
But since the answer choices are given in whole numbers, we can convert this to minutes:
0.5652 hours * 60 minutes/hour = 33.91 minutes
Rounding to the nearest whole number, Iris will take approximately 34 minutes to complete the entire floor.
Therefore, the correct answer is: 34 minutes.