To find out how long it will take Iris to complete the entire gymnasium floor, we start by determining her rate:
Iris completes \( \frac{2}{3} \) of the floor in \( \frac{1}{2} \) hour.
First, we can find her rate (the fraction of the floor she completes in one hour) by scaling up her completion:
If she completes \( \frac{2}{3} \) of the floor in \( \frac{1}{2} \) hour, we can find the completion per hour as follows:
\[
\text{Completion rate} = \left(\frac{2}{3} \div \frac{1}{2}\right) = \frac{2}{3} \times \frac{2}{1} = \frac{4}{3} \text{ of the floor per hour}.
\]
Now, if she completes \( \frac{4}{3} \) of the floor in one hour, we can determine how long it will take her to complete the entire floor (1 floor):
\[
\text{Time to complete 1 floor} = \frac{1 \text{ floor}}{\frac{4}{3} \text{ floors/hour}} = \frac{1 \times 3}{4} = \frac{3}{4} \text{ hours}.
\]
So, it will take her \( \frac{3}{4} \) hours to complete the entire floor.
To convert \( \frac{3}{4} \) hours into hours and minutes:
- \( \frac{3}{4} \) hours is equivalent to \( 45 \) minutes.
Thus, the answer to how long it will take her to complete the entire floor is 1 hour.