Final answer:
To calculate the unit rate of birdhouses Joe built, divide the total number of birdhouses by the total hours spent, resulting in 6 birdhouses per hour.
Step-by-step explanation:
The question is asking for the unit rate at which Joe builds birdhouses. The unit rate is the amount of something per one unit of another thing; in this case, how many birdhouses Joe can build per hour. To find the unit rate, you divide the total number of birdhouses built by the total number of hours it took to build them.
Joe built 30 birdhouses in 5 hours. Using the formula for unit rate, which is:
Unit Rate = Total Quantity / Total Time
Unit Rate = 30 birdhouses / 5 hours = 6 birdhouses per hour
Therefore, the correct answer is a) 6 birdhouses per hour.