Answer: Randy's house number is 39.
Step-by-step explanation: Given that a group of students have the following house numbers:
29, 39, 59, and 79.
Also, Randy's house number is a composite number.
We are to find Randy's house number.
The first number is 29. It has only two factors 1 and 29. So, it is a prime number.
This cannot be Randy's house number.
The second number is 39. It has four factors 1, 3, 13 and 39. So, it is not a prime number, a composite number.
This is Randy's house number.
The third number is 59. It has only two factors 1 and 59. So, it is a prime number.
This cannot be Randy's house number.
The first number is 79. It has only two factors 1 and 29. So, it is a prime number.
This cannot be Randy's house number.
Thus, Randy's house number is 39.