1. Look at the numbers below. Label each as prime or composite. A. 39 __ B. 31 __ C. 7 __ D. 55 __ 2. Simplify the problem in the box. 9times 10^4 (C) 1times 10^5 (B) 1times 10^4 (D) 9times 10^5 (1times 10^4)times (9times 10^1)

1. <br />A. 39 is a composite number because it has factors other than 1 and itself, such as 3 and 13.<br />B. 31 is a prime number because it only has two factors, 1 and itself.<br />C. 7 is a prime number because it only has two factors, 1 and itself.<br />D. 55 is a composite number because it has factors other than 1 and itself, such as 5 and 11.<br /><br />2. To simplify the problem in the box, we need to multiply the numbers inside the parentheses and then multiply the result by $10^{4}$.<br /><br />$(1\times 10^{4})\times (9\times 10^{1}) = 9\times 10^{5}$<br /><br />Therefore, the correct answer is (D) $9\times 10^{5}$.