Kirk has 1.5 hours (or 1 hour and 30 minutes) to complete the test. If he has used \(\frac{1}{3}\) of his time already, we can calculate how much time he has used.
First, we find \(\frac{1}{3}\) of 1.5 hours:
\[ \text{Time used} = \frac{1}{3} \times 1.5 \text{ hours} \]
To make the calculation easier, we can convert 1.5 hours to a fraction:
\[ 1.5 \text{ hours} = \frac{3}{2} \text{ hours} \]
Now, calculate \(\frac{1}{3} \times \frac{3}{2}\):
\[ \frac{1}{3} \times \frac{3}{2} = \frac{1 \times 3}{3 \times 2} = \frac{3}{6} = \frac{1}{2} \text{ hours} \]
Thus, Kirk has used \(\frac{1}{2}\) hour, which is equivalent to 30 minutes.
Therefore, the answer is:
\(\frac{1}{2}\) hour